Aqueous cleaning compositions including an alkyl 3-hydroxybutyrate

ABSTRACT

Cleaning compositions and methods of making and using the same are provided. The cleaning compositions of the present invention may include at least one alkyl 3-hydroxybutyrate and water, optionally including at least one surfactant and one or more additional additives. The cleaning compositions of the present invention, which are non-toxic and environmentally benign, can be useful to remove many types of soils from a range of different substrates in a variety of domestic, industrial, and/or institutional applications.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.13/957,616, filed Aug. 2, 2013. The entire disclosure of theabove-referenced application is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to cleaning compositions that are useful forcleaning a variety of substrates. This invention further relates tomethods of making and using such compositions.

BACKGROUND

Aqueous cleaning compositions are useful for removing dirt and othersoils from a variety of surfaces including hard surfaces such as floors,walls, countertops, and furniture. Many commercially-available aqueouscleaners include an organic solvent combined with water and optionalingredients such as surfactants, colorants, fragrances, and the like.Makers of these cleaning compositions, whether for household,industrial, or institutional use, are faced with the task of optimizingthe cleaning formulations by selecting a solvent that exhibits excellentcleaning performance, but that causes minimum adverse effects on theuser and the environment. To date, this problem has not beensuccessfully resolved, as most high performance cleaning compositions donot have benign toxicity profiles and/or include high VOC solvents,while many “green” cleaners, recently developed in light of stricterenvironmental regulations, exhibit unsatisfactory cleaning performance.

Thus, a need exists for a safe, environmentally friendly cleaningcomposition capable of removing soil from a substrate with highefficiency. Preferably, the cleaning composition would be effective toremove a variety of types of undesirable substances from a wide range ofsubstrates. Further, the cleaning composition should be able to bemanufactured in a cost-effective manner and on a commercial scale.

SUMMARY

In one aspect, the present invention concerns an aqueous cleaningcomposition comprising water and at least 0.1 weight percent of at leastone alkyl 3-hydroxybutyrate defined by the following formula:

wherein R1 is an alkyl group having at least three and not more thanfive carbon atoms.

In another aspect, the present invention concerns a method for cleaninga substrate comprising contacting a substrate with a cleaningcomposition comprising water and at least one alkyl 3-hydroxybutyratedefined by the following formula:

wherein R1 is an alkyl group having at least three and not more thanfive carbon atoms.

In yet another aspect, the present invention concerns a method formaking a cleaning composition, the method comprising: combining an alkyl3-hydroxybutyrate with water and an optional surfactant to therebyprovide a cleaning mixture, wherein the alkyl group of the alkyl3-hydroxybutyrate has at least three and not more than five carbonatoms.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the present invention are described in detail belowwith reference to the attached drawing figures, wherein:

FIG. 1 depicts the results of a baked grease scrub test performed usingseveral comparative and inventive cleaning compositions to remove bakedgrease from an aluminum panel using the method described in Example 4;

FIG. 2 depicts the results of a tar-aluminum scrub test performed usingseveral comparative and inventive cleaning compositions to remove tarfrom an aluminum panel using the method described in Example 4;

FIG. 3 a depicts the results of a soap scum scrub test performed using acomparative and an inventive cleaning composition to remove soap scumfrom a painted wall board panel using the method described in Example 4;

FIG. 3 b depicts the results of a soap scum scrub test performed usingseveral comparative cleaning compositions to remove soap scum from apainted wall board panel using the method described in Example 4;

FIG. 3 c depicts the results of a soap scum scrub test performed usingseveral other comparative cleaning compositions to remove soap scum froma painted wall board panel using the method described in Example 4;

FIG. 4 depicts the results of a tar-vinyl scrub test performed usingseveral comparative and inventive cleaning compositions to remove tarfrom a vinyl panel using the method described in Example 4; and

FIG. 5 depicts the results of a wax scrub test performed using severaldifferent solvents on a vinyl floor tile coated with black-tinted wax asdescribed in Example 5 to demonstrate the interaction of each solventwith the wax coating.

DETAILED DESCRIPTION

The present invention relates to aqueous cleaning compositions suitablefor removing one or more soils from a substrate. As used herein, theterm “soil” refers to any composition or material whose presence on aparticular substrate is undesirable. Examples of soils can include, butare not limited to, dirt, tar, grease, oil, soap scum, protein,organics, enzymes, and combinations thereof. The cleaning compositionsof the present invention can exhibit a high cleaning efficiency for avariety of soils and substrates, while exhibiting a benign toxicityprofile and being environmentally compatible.

The cleaning compositions of the present invention can be aqueouscleaning compositions including water and at least one organic,ester-based solvent. The ester-based solvent may include at least onealkyl 3-hydroxybutyrate defined by formula (I), below:

wherein R1 is an alkyl group comprising at least 3 and not more than 5carbon atoms. As used herein, the term “alkyl group,” refers to abranched or straight-chain monovalent alkyl radical. The alkyl grouprepresented by R1 in formula (I) above may include 3 or 4 carbon atoms,or may include 4 carbon atoms. The R1 group may be selected from thegroup consisting of isopropyl, n-propyl, isobutyl, n-butyl, 2-butyl(sec-butyl), 2,2-dimethylethyl (tert-butyl), 3,3-dimethylpentyl(isopentyl), 1-pentyl (n-pentyl), 1-methylbutyl(2-pentyl),2-methylbutyl, 2-ethylpropyl(3-pentyl), 1,1-dimethylpropyl,1,2-dimethylpropyl, 2,2-dimethylpropyl (neopentyl), and cyclopentyl, ormay be selected from the group consisting of isopropyl, n-propyl,isobutyl, n-butyl, and 2-butyl. In some cases, the alkyl group R1 may beselected from the group consisting of isopropyl, isobutyl, n-butyl, and2-butyl or the group consisting of isobutyl, n-butyl, and 2-butyl. Also,the R1 group can be n-butyl. The alkyl 3-hydroxybutyrate may be presentas a single enantiomer, a mixture of enantiomers enriched in oneenantiomer, a single diasteriomer, a mixture enriched in onediasteriomer, or as a racemic mixture. The alkyl 3-hydroxybutyrate maybe non-halogenated.

The alkyl 3-hydroxybutyrate may have a vapor pressure, measured at 20°C. via ASTM D-1160, of not more than about 0.20 torr, not more thanabout 0.18 torr, not more than about 0.16 torr, or not more than about0.12 torr. In some cases, the alkyl 3-hydroxybutyrate may have a vaporpressure at 20° C. of at least about 0.05 torr, at least about 0.055torr, at least about 0.06 torr, and/or not more than about 0.10 torr,not more than about 0.09 torr, not more than about 0.08 torr, not morethan about 0.075 torr. The alkyl 3-hydroxybutyrate can have a vaporpressure, measured at 20° C., in the range of from about 0.05 to about0.10 torr, about 0.05 to about 0.09 torr, about 0.05 to about 0.08 torr,about 0.05 to about 0.075 torr, about 0.055 to about 0.10 torr, about0.055 to about 0.09 torr, about 0.055 to about 0.08 torr, about 0.055 toabout 0.075 torr, about 0.06 to about 0.10 torr, about 0.06 to about0.09 torr, about 0.06 to about 0.08 torr, about 0.06 to about 0.075torr.

The alkyl 3-hydroxybutyrate may also have a boiling point, measured atatmospheric pressure using a Mettler FP81HT MBC cell equipped withphotocell detection, of at least about 150° C., at least about 200° C.,at least about 210° C., at least about 215° C., at least about 216° C.,or at least about 217° C. and/or not more than about 230° C., not morethan about 225° C., or not more than about 220° C. The boiling point ofthe alkyl 3-hydroxybutyrate can be in the range of from about 150 toabout 230° C., about 150 to about 225° C., about 150 to about 220° C.,about 200 to about 230° C., about 200 to about 225° C., about 200 toabout 220° C., about 210 to about 230° C., about 210 to about 225° C.,about 210 to about 220° C., about 215 to about 230° C., about 215 toabout 225° C., about 215 to about 220° C., about 216 to about 230° C.,about 216 to about 225° C., about 216 to about 220° C., about 217 toabout 230° C., about 217 to about 225° C., about 217 to about 220° C.

The alkyl 3-hydroxybutyrate can have a flash point, measured by ASTMD7236-07 with a Setaflash closed cup instrument, of at least about 80°C., at least about 85° C., at least about 90° C., at least about 95° C.and/or not more than about 115° C., not more than about 110° C., notmore than about 105° C. and/or may have an auto-ignition temperature,measured according to ASTM E659-78 (2005), of at least about 290° C., atleast about 295° C., at least about 300° C. and/or not more than about345° C., not more than about 335° C., or not more than about 330° C. Thealkyl 3-hydroxybutyrate of the cleaning composition may have a flashpoint in the range of from about 80 to about 115° C., about 80 to about110° C., about 80 to about 105° C., about 85 to about 115° C., about 85to about 110° C., about 85 to about 105° C., about 90 to about 115° C.,about 90 to about 110° C., about 90 to about 105° C., from about 95 toabout 115° C., about 95 to about 110° C., or about 95 to about 105° C.and/or an auto-ignition temperature in the range of from about 290 toabout 345° C., about 290 to about 335° C., about 290 to about 330° C.,about 295 to about 345° C., about 295 to about 335° C., about 295 toabout 330° C., about 300 to about 345° C., about 300 to about 335° C.,or about 300 to about 330° C.

The alkyl 3-hydroxybutyrate may also have a density, measured at 20° C.using ASTM D4052-11, of at least about 0.955 g/mL, at least about 0.960g/mL, at least about 0.965 g/mL, at least about 0.970 g/mL and/or notmore than about 0.985 g/mL, not more than about 0.980 g/mL, or not morethan about 0.975 g/mL. The alkyl 3-hydroxybutyrate may have a density inthe range of from about 0.955 to about 0.985 g/mL, about 0.955 to about0.980 g/mL, about 0.955 to 0.975 g/mL, 0.960 to about 0.985 g/mL, about0.960 to about 0.980 g/mL, about 0.960 to 0.975 g/mL, 0.965 to about0.985 g/mL, about 0.965 to about 0.980 g/mL, about 0.965 to 0.975 g/mL,0.970 to about 0.985 g/mL, about 0.970 to about 0.980 g/mL, about 0.970to 0.975 g/mL.

The alkyl 3-hydroxybutyrate can have a solubility limit in deionizedwater at 23° C. of at least about 2 weight percent, at least about 2.5weight percent, at least about 3 weight percent, at least about 3.5weight percent, at least about 3.75 weight percent and/or not more thanabout 20 weight percent, not more than about 15 weight percent, not morethan about 10 weight percent, not more than about 5 weight percent. Thesolubility limit of the alkyl 3-hydroxybutyrate in deionized water at23° C. can be in the range of from about 2 to about 20 weight percent,about 2 to about 15 weight percent, about 2 to about 10 weight percent,about 2 to about 5 weight percent, about 2.5 to about 20 weight percent,about 2.5 to about 15 weight percent, about 2.5 to about 10 weightpercent, about 2.5 to about 5 weight percent, about 3 to about 20 weightpercent, about 3 to about 15 weight percent, about 3 to about 10 weightpercent, about 3 to about 5 weight percent, about 3.5 to about 20 weightpercent, about 3.5 to about 15 weight percent, about 3.5 to about 10weight percent, about 3.5 to about 5 weight percent, about 3.75 to about20 weight percent, about 3.75 to about 15 weight percent, about 3.75 toabout 10 weight percent, about 3.75 to about 5 weight percent.

The solubility limit of deionized water at 23° C. in the alkyl3-hydroxybutyrate may be at least about 6 weight percent, at least about8 weight percent, at least about 10 weight percent and/or not more thanabout 25 weight percent, not more than about 20 weight percent, not morethan about 12 weight percent. The solubility limit of deionized water at23° C. in the alkyl 3-hydroxybutyrate can be in the range of from about6 to about 25 weight percent, about 6 to about 15 weight percent, about6 to about 12 weight percent, about 8 to about 25 weight percent, about8 to about 15 weight percent, about 8 to about 12 weight percent, about10 to about 25 weight percent, about 10 to about 15 weight percent,about 10 to about 12 weight percent.

Additionally, the alkyl 3-hydroxybutyrate may be described by one ormore of the following Hansen solubility parameters. For example, thealkyl 3-hydroxybutyrate may have a Hansen polar solubility parameter(σ_(p) or “P parameter”) of at least about 2.50 (cal/cm³)^(1/2), atleast about 2.75 (cal/cm³)^(1/2), at least about 2.80 (cal/cm³)^(1/2),at least about 2.95 (cal/cm³)^(1/2), at least about 3.00(cal/cm³)^(1/2), at least about 3.10 (cal/cm³)^(1/2) and/or not morethan about 3.4 (cal/cm³)^(1/2), not more than about 3.30(cal/cm³)^(1/2), not more than about 3.25 (cal/cm³)^(1/2), calculatedusing the “Hansen Solubility Parameters in Practice” software package3^(rd) ed., version 3.1, by S. Abbott and C. Hansen.

The Hansen polar solubility parameter, which measures the permanentdipole moment and permanent dipole interactions of a molecule, can be inthe range of from about 2.5 to about 3.4 (cal/cm³)^(1/2), about 2.5 toabout 3.3 (cal/cm³)^(1/2), about 2.5 to about 3.25 (cal/cm³)^(1/2), 2.75to about 3.4 (cal/cm³)^(1/2), about 2.75 to about 3.3 (cal/cm³)^(1/2),about 2.75 to about 3.25 (cal/cm³)^(1/2), 2.8 to about 3.4(cal/cm³)^(1/2), about 2.8 to about 3.3 (cal/cm³)^(1/2), about 2.8 toabout 3.25 (cal/cm³)^(1/2), 2.95 to about 3.4 (cal/cm³)^(1/2), about2.95 to about 3.3 (cal/cm³)^(1/2), about 2.95 to about 3.25(cal/cm³)^(1/2), 3.0 to about 3.4 (cal/cm³)^(1/2), about 3.0 to about3.3 (cal/cm³)^(1/2), about 3.0 to about 3.25 (cal/cm³)^(1/2), 3.1 toabout 3.4 (cal/cm³)^(1/2), about 3.1 to about 3.3 (cal/cm³)^(1/2), about3.1 to about 3.25 (cal/cm³)^(1/2) for the alkyl 3-hydroxybutyrate.

The alkyl 3-hydroxybutyrate can have a Hansen hydrogen bondingsolubility parameter (σ_(h) or “H parameter”) of at least about 5.40(cal/cm³)^(1/2), at least about 5.40 (cal/cm³)^(1/2), at least about5.60 (cal/cm³)^(1/2), at least about 5.65 (cal/cm³)^(1/2), at leastabout 5.70 (cal/cm³)^(1/2) and/or not more than about 6.10(cal/cm³)^(1/2), not more than about 5.95 (cal/cm³)^(1/2), not more thanabout 5.90 (cal/cm³)^(1/2), not more than about 5.85 (cal/cm³)^(1/2),calculated as described above.

The Hansen hydrogen bonding solubility parameter, which measureselectron exchange, can be in the range of from about 5.40 to about 6.10(cal/cm³)^(1/2), about 5.40 to about 5.95 (cal/cm³)^(1/2), about 5.40 toabout 5.90 (cal/cm³)^(1/2), about 5.40 to about 5.85 (cal/cm³)^(1/2)about 5.60 to about 6.10 (cal/cm³)^(1/2), about 5.60 to about 5.95(cal/cm³)^(1/2), about 5.60 to about 5.90 (cal/cm³)^(1/2), about 5.60 toabout 5.85 (cal/cm³)^(1/2), about 5.65 to about 6.10 (cal/cm³)^(1/2),about 5.65 to about 5.95 (cal/cm³)^(1/2), about 5.65 to about 5.90(cal/cm³)^(1/2), about 5.65 to about 5.85 (cal/cm³)^(1/2), about 5.70 toabout 6.10 (cal/cm³)^(1/2), about 5.70 to about 5.95 (cal/cm³)^(1/2),about 5.70 to about 5.90 (cal/cm³)^(1/2), about 5.70 to about 5.85(cal/cm³)^(1/2) for the alkyl 3-hydroxybutyrate.

The alkyl 3-hydroxybutyrate can have a Hansen dispersion solubilityparameter (ad or “D parameter”) of at least about 7.50 (cal/cm³)^(1/2),at least about 7.75 (cal/cm³)^(1/2), at least about 8.00(cal/cm³)^(1/2), at least about 8.03 (cal/cm³)^(1/2) and/or not morethan about 8.15 (cal/cm³)^(1/2), not more than about 8.10(cal/cm³)^(1/2), not more than about 8.05 (cal/cm³)^(1/2), not more thanabout 8.00 (cal/cm³)^(1/2), calculated as described above.

The Hansen dispersion solubility parameter, which measures nonpolarinteractions derived from atomic forces, of the alkyl 3-hydroxybutyratecan be in the range of from about 7.50 to about 8.15 (cal/cm³)^(1/2),about 7.50 to about 8.10 (cal/cm³)^(1/2), about 7.50 to about 8.05(cal/cm³)^(1/2), about 7.50 to about 8.0 (cal/cm³)^(1/2), about 7.75 toabout 8.15 (cal/cm³)^(1/2), about 7.75 to about 8.10 (cal/cm³)^(1/2),about 7.75 to about 8.05 (cal/cm³)^(1/2), about 7.75 to about 8.0(cal/cm³)^(1/2), about 8.0 to about 8.15 (cal/cm³)^(1/2), about 8.0 toabout 8.10 (cal/cm³)^(1/2), about 8.0 to about 8.05 (cal/cm³)^(1/2),about 8.03 to about 8.15 (cal/cm³)^(1/2), about 8.03 to about 8.10(cal/cm³)^(1/2), about 8.03 to about 8.05 (cal/cm³)^(1/2).

The alkyl 3-hydroxybutyrate can have a total Hansen solubility parameterof at least about 10.1 (cal/cm³)^(1/2), at least about 10.2(cal/cm³)^(1/2), at least about 10.25 (cal/cm³)^(1/2), at least about10.3 (cal/cm³)^(1/2) and/or not more than about 10.5 (cal/cm³)^(1/2),not more than about 10.45 (cal/cm³)^(1/2), not more than about 10.40(cal/cm³)^(1/2), calculated as described above. The total Hansensolubility parameter of the alkyl 3-hydroxybutyrate can be in the rangeof from about 10.1 to about 10.5 (cal/cm³)^(1/2), about 10.1 to about10.45 (cal/cm³)^(1/2), about 10.1 to about 10.40 (cal/cm³)^(1/2), about10.2 to about 10.5 (cal/cm³)^(1/2), about 10.2 to about 10.45(cal/cm³)^(1/2), about 10.2 to about 10.40 (cal/cm³)^(1/2), about 10.25to about 10.5 (cal/cm³)^(1/2), about 10.25 to about 10.45(cal/cm³)^(1/2), about 10.25 to about 10.40 (cal/cm³)^(1/2), about 10.3to about 10.5 (cal/cm³)^(1/2), about 10.3 to about 10.45(cal/cm³)^(1/2), about 10.3 to about 10.40 (cal/cm³)^(1/2).

The alkyl 3-hydroxybutyrate can have a surface tension, measured usingthe ring pull method with a Krüss K100 tensiometer, of at least about24.5 dynes/cm, at least about 25.0 dynes/cm, at least about 25.5dynes/cm, and/or not more than about 30 dynes/cm, not more than about 29dynes/cm, not more than about 28 dynes/cm, not more than about 27dynes/cm, not more than about 26.5 dynes/cm. The surface tension of thealkyl 3-hydroxybutyrate can be in the range of from about 24.5 to about30 dynes/cm, about 24.5 to about 29 dynes/cm, about 24.5 to about 28dynes/com, about 24.5 to about 27 dynes/cm, about 24.5 to about 26.5dynes/cm, about 25 to about 30 dynes/cm, about 25 to about 29 dynes/cm,about 25 to about 28 dynes/com, about 25 to about 27 dynes/cm, about 25to about 26.5 dynes/cm, about 25.5 to about 30 dynes/cm, about 25.5 toabout 29 dynes/cm, about 25.5 to about 28 dynes/com, about 25.5 to about27 dynes/cm, about 25.5 to about 26.5 dynes/cm.

The alkyl 3-hydroxybutyrate may also have the ability to bring togetherand homogenize two immiscible liquids, for example, an oil and water.This ability is called “coupling efficiency” and can be measured byadding the alkyl 3-hydroxybutyrate to 1.0 gram of an oil and 1.0 gram ofdeionized water with vigorous stirring or shaking until the mixturebecomes clear. The result can then be expressed as the number of gramsof solvent divided by the total grams of oil and water. The alkyl3-hydroxybutyrate can have a corn oil-water coupling efficiency measuredat 23° C. of at least about 5 grams of alkyl 3-hydroxybutyrate per totalgrams of oil and water (g/g), at least about 6 g/g, at least about 7 g/gand/or not more than about 15 g/g, not more than about 12 g/g, or notmore than about 10 g/g. The alkyl 3-hydroxybutyrate may also have a cornoil-water coupling efficiency in the range of from about 5 to about 15g/g, about 5 to about 12 g/g, about 5 to about 10 g/g, about 6 to about15 g/g, about 6 to about 12/g/g, about 6 to about 10 g/g, about 7 toabout 15 g/g, about 7 to about 12 g/g, about 7 to about 10 g/g.

The alkyl 3-hydroxybutyrate can originate from any suitable sourceand/or can be synthesized by any suitable method. It may, for example,originate from a biological source and be obtained by alcoholysis of apoly-3-hydroxybutyrate (PHB) extracted from plant matter or otherbiological materials. It may be synthesized directly by esterificationof 3-hydroxybutyric acid or by transesterification of a different3-hydroxybutric acid ester, for example, methyl 3-hydroxybutyrate, andan alkanol in the presence of an aprotic catalyst, for example, adialkyl tin oxide.

It may also be synthesized by reducing an alkyl acetoacetate, forexample, in the presence of hydrogen and a hydrogenation catalyst at atemperature of at least about 70° C., at least about 75° C., or at leastabout 80° C. and/or not more than about 110° C., not more than about105° C., or not more than about 95° C. The temperature of hydrogenationmay be in the range of from about 70° C. to about 110° C., about 70° C.to about 105° C., about 70° C. to about 95° C., about 75° C. to about110° C., about 75° C. to about 105° C., about 75° C. to about 95° C.,about 80° C. to about 110° C., about 80° C. to about 105° C., about 80°C. to about 95° C. The hydrogenation pressure may be at least about 700psig, at least about 750 psig, at least about 800 psig and/or not morethan about 1200 psig, not more than about 1000 psig, or not more thanabout 900 psig, or in the range of from about 700 to about 1200 psig,about 700 to about 1000 psig, about 700 to about 900 psig, about 750 toabout 1200 psig, about 750 to about 1000 psig, about 750 to about 900psig, about 800 to about 1200 psig, about 800 to about 1000 psig, about800 to about 900 psig.

The cleaning composition of the present invention may include at least0.1 weight percent of the alkyl 3-hydroxybutyrate, based on the totalweight of the composition. The alkyl 3-hydroxybutyrate may also bepresent in an amount of at least about 0.5 weight percent, at leastabout 1 weight percent, at least about 2 weight percent, at least about3 weight percent, at least about 4 weight percent, at least about 5weight percent and/or not more than about 99 weight percent, not morethan about 90 weight percent, not more than about 80 weight percent, notmore than about 70 weight percent, not more than about 60 weightpercent, not more than about 50 weight percent, not more than about 40weight percent, not more than about 30 weight percent, not more thanabout 20 weight percent, not more than about 15 weight percent, not morethan about 10 weight percent, not more than about 5 weight percent, notmore than about 4 weight percent, based on the total weight of thecomposition.

The alkyl 3-hydroxybutyrate can be present in the cleaning compositionin an amount in the range of from about 0.1 to about 99 weight percent,about 0.1 to about 90 weight percent, about 0.1 to about 80 weightpercent, about 0.1 to about 70 weight percent, about 0.1 to about 60weight percent, about 0.1 to about 50 weight percent, about 0.1 to about40 weight percent, about 0.1 to about 30 weight percent, about 0.1 toabout 20 weight percent, about 0.1 to about 15 weight percent, about 0.1to about 10 weight percent, about 0.1 to about 5 weight percent, about0.1 to about 4 weight percent, about 0.5 to about 99 weight percent,about 0.5 to about 90 weight percent, about 0.5 to about 80 weightpercent, about 0.5 to about 70 weight percent, about 0.5 to about 60weight percent, about 0.5 to about 50 weight percent, about 0.5 to about40 weight percent, about 0.5 to about 30 weight percent, about 0.5 toabout 20 weight percent, about 0.5 to about 15 weight percent, about 0.5to about 10 weight percent, about 0.5 to about 5 weight percent, about0.5 to about 4 weight percent, about 1 to about 99 weight percent, about1 to about 90 weight percent, about 1 to about 80 weight percent, about1 to about 70 weight percent, about 1 to about 60 weight percent, about1 to about 50 weight percent, about 1 to about 40 weight percent, about1 to about 30 weight percent, about 1 to about 20 weight percent, about1 to about 15 weight percent, about 1 to about 10 weight percent, about1 to about 5 weight percent, about 1 to about 4 weight percent, about 2to about 99 weight percent, about 2 to about 90 weight percent, about 2to about 80 weight percent, about 2 to about 70 weight percent, about 2to about 60 weight percent, about 2 to about 50 weight percent, about 2to about 40 weight percent, about 2 to about 30 weight percent, about 2to about 20 weight percent, about 2 to about 15 weight percent, about 2to about 10 weight percent, about 2 to about 5 weight percent, about 2to about 4 weight percent, about 3 to about 99 weight percent, about 3to about 90 weight percent, about 3 to about 80 weight percent, about 3to about 70 weight percent, about 3 to about 60 weight percent, about 3to about 50 weight percent, about 3 to about 40 weight percent, about 3to about 30 weight percent, about 3 to about 20 weight percent, about 3to about 15 weight percent, about 3 to about 10 weight percent, about 3to about 5 weight percent, about 3 to about 4 weight percent, about 4 toabout 99 weight percent, about 4 to about 90 weight percent, about 4 toabout 80 weight percent, about 4 to about 70 weight percent, about 4 toabout 60 weight percent, about 4 to about 50 weight percent, about 4 toabout 40 weight percent, about 4 to about 30 weight percent, about 4 toabout 20 weight percent, about 4 to about 15 weight percent, about 4 toabout 10 weight percent, about 4 to about 5 weight percent, about 5 toabout 99 weight percent, about 5 to about 90 weight percent, about 5 toabout 80 weight percent, about 5 to about 70 weight percent, about 5 toabout 60 weight percent, about 5 to about 50 weight percent, about 5 toabout 40 weight percent, about 5 to about 30 weight percent, about 5 toabout 20 weight percent, about 5 to about 15 weight percent, or about 5to about 10 weight percent, based on the total weight of thecomposition. The amount of the alkyl 3-hydroxybutyrate used in thecleaning composition may depend, in part, on the specific application,the type of substrate being cleaned, and/or type of soil being removed.

The water may be present in the aqueous cleaning composition in anamount of at least about 30 weight percent, at least about 35 weightpercent, at least about 40 weight percent, at least about 45 weightpercent, at least about 50 weight percent, at least about 55 weightpercent, at least about 60 weight percent, at least about 65 weightpercent, at least about 70 weight percent, at least about 75 weightpercent, and/or not more than about 99.9 weight percent, not more thanabout 95 weight percent, not more than about 90 weight percent, not morethan about 85 weight percent, not more than about 80 weight percent,based on the total weight of the cleaning composition.

Water may be present in the cleaning composition in an amount in therange of from about 30 to about 99.9 weight percent, about 30 to about95 weight percent, about 30 to about 90 weight percent, about 30 toabout 85 weight percent, about 30 to about 80 weight percent, 35 toabout 99.9 weight percent, about 35 to about 95 weight percent, about 35to about 90 weight percent, about 35 to about 85 weight percent, about35 to about 80 weight percent, 40 to about 99.9 weight percent, about 40to about 95 weight percent, about 40 to about 90 weight percent, about40 to about 85 weight percent, about 40 to about 80 weight percent, 45to about 99.9 weight percent, about 45 to about 95 weight percent, about45 to about 90 weight percent, about 45 to about 85 weight percent,about 45 to about 80 weight percent, about 50 to about 99.9 weightpercent, about 50 to about 95 weight percent, about 50 to about 90weight percent, about 50 to about 85 weight percent, about 50 to about80 weight percent, about 55 to about 99.9 weight percent, about 55 toabout 95 weight percent, about 55 to about 90 weight percent, about 55to about 85 weight percent, about 55 to about 80 weight percent, about60 to about 99.9 weight percent, about 60 to about 95 weight percent,about 60 to about 90 weight percent, about 60 to about 85 weightpercent, about 60 to about 80 weight percent, about 65 to about 99.9weight percent, about 65 to about 95 weight percent, about 65 to about90 weight percent, about 65 to about 85 weight percent, about 65 toabout 80 weight percent, about 70 to about 99.9 weight percent, about 70to about 95 weight percent, about 70 to about 90 weight percent, about70 to about 85 weight percent, about 70 to about 80 weight percent,based on the total weight of the composition.

The ratio, by weight, of alkyl 3-hydroxybutyrate to water in thecleaning composition may be at least about 0.001:1, at least about0.002:1, at least about 0.005:1, at least about 0.010:1 at least about0.020:1 and/or not more than about 0.50:1, not more than about 0.25:1,not more than about 0.20:1, not more than about 0.10:1, not more thanabout 0.05:1, not more than about 0.035:1, or in the range of from about0.001:1 to about 0.50:1, about 0.001:1 to about 0.25:1, about 0.001:1 toabout 0.20:1, about 0.001:1 to about 0.10:1, about 0.001:1 to about0.05:1, about 0.001:1 to about 0.035:1, about 0.002:1 to about 0.50:1,about 0.002:1 to about 0.25:1, about 0.002:1 to about 0.20:1, about0.002:1 to about 0.10:1, about 0.002:1 to about 0.05:1, about 0.002:1 toabout 0.035:1, about 0.005:1 to about 0.50:1, about 0.005:1 to about0.25:1, about 0.005:1 to about 0.20:1, about 0.005:1 to about 0.10:1,about 0.005:1 to about 0.05:1, about 0.005:1 to about 0.035:1, about0.010:1 to about 0.50:1, about 0.010:1 to about 0.25:1, about 0.010:1 toabout 0.20:1, about 0.010:1 to about 0.10:1, about 0.010:1 to about0.05:1, about 0.010:1 to about 0.035:1, about 0.020:1 to about 0.50:1,about 0.020:1 to about 0.25:1, about 0.020:1 to about 0.20:1, about0.020:1 to about 0.10:1, about 0.020:1 to about 0.05:1, about 0.020:1 toabout 0.035:1.

The water may be any type of water suitable for use in a cleaningcomposition and can originate from several sources. For example, thewater can include tap water, filtered water, bottled water, springwater, distilled water, deionized water, and/or industrial soft water.If the water is hard water comprising organics and/or dissolved mineralsalts or metals, it may be purified to remove all or at least a portionof these components, which may interfere with the operation of the othercomponents of the cleaning composition.

The cleaning composition may include not more than about 10 weightpercent, not more than about 8 weight percent, not more than about 5weight percent, not more than about 2 weight percent, not more thanabout 1 weight percent, not more than about 0.5 weight percent, not morethan about 0.1 weight percent of components other than water and thealkyl 3-hydroxybutyrate, based on the total weight of all ingredients inthe composition. In other cases, the composition may consist essentiallyof water and the alkyl 3-hydroxybutyrate. The alkyl 3-hydroxybutyratemay be present in the cleaning composition in an amount of not more thanabout 5 weight percent, not more than about 4.5 weight percent, or notmore than about 4 weight percent, based on the total weight of thecomposition. The cleaning composition may comprise not more than about10 weight percent, not more than about 8 weight percent, not more thanabout 6 weight percent, not more than about 5 weight percent, not morethan about 4 weight percent, not more than about 3 weight percent, notmore than about 2 weight percent, not more than about 1 weight percent,not more than about 0.5 weight percent of one or more components havinga vapor pressure greater than about 0.10 torr measured at 20° C.

Cleaning compositions of the present invention may also include at leastone surfactant. As used herein, the term “surfactant,” refers to acompound that reduces surface tension when dissolved in water or watersolutions or that reduces the interfacial tension between two liquids orbetween a liquid and a solid. The surfactant, when present alone or as asystem comprising two or more surfactants, may be included in thecleaning composition in an amount of at least about 0.01 weight percent,at least about 0.05 weight percent, at least about 1 weight percent, atleast about 1.5 weight percent, at least about 2 weight percent and/ornot more than about 15 weight percent, not more than about 10 weightpercent, not more than about 8 weight percent, not more than about 6weight percent, not more than about 4 weight percent, based on the totalweight of the composition.

The surfactant may be present in the composition in an amount in therange of about 0.01 weight percent to about 15 weight percent, about0.01 to about 10 weight percent, about 0.01 to about 8 weight percent,about 0.01 to about 6 weight percent, about 0.01 to about 4 weightpercent, about 0.05 to about 15 weight percent, about 0.05 to about 10weight percent, about 0.05 to about 8 weight percent, about 0.05 toabout 6 weight percent, about 0.05 to about 4 weight percent, about 1 toabout 15 weight percent, about 1 to about 10 weight percent, about 1 toabout 8 weight percent, about 1 to about 6 weight percent, about 1 toabout 4 weight percent, about 1.5 to about 15 weight percent, about 1.5to about 10 weight percent, about 1.5 to about 8 weight percent, about1.5 to about 6 weight percent, about 1.5 to about 4 weight percent,about 2 to about 15 weight percent, about 2 to about 10 weight percent,about 2 to about 8 weight percent, about 2 to about 6 weight percent,about 2 to about 4 weight percent, based on the total weight of thecomposition.

The ratio, by weight, of the alkyl 3-hydroxybutyrate to surfactant inthe cleaning composition may be at least about 0.01:1, at least about0.05:1, at least about 0.10:1, at least about 0.5:1 and/or not more thanabout 150:1, not more than about 100:1, not more than about 50:1, notmore than about 25:1, not more than about 10:1, not more than about 5:1,or in the range of from about 0.01:1 to about 150:1, about 0.01:1 toabout 100:1, about 0.01:1 to about 50:1, about 0.01:1 to about 25:1,about 0.01:1 to about 10:1, about 0.01:1 to about 5:1, about 0.05:1 toabout 150:1, about 0.05:1 to about 100:1, about 0.05:1 to about 50:1,about 0.05:1 to about 25:1, about 0.05:1 to about 10:1, about 0.05:1 toabout 5:1, about 0.10:1 to about 150:1, about 0.10:1 to about 100:1,about 0.10:1 to about 50:1, about 0.10:1 to about 25:1, about 0.10:1 toabout 10:1, about 0.10:1 to about 5:1, about 0.5:1 to about 150:1, about0.5:1 to about 100:1, about 0.5:1 to about 50:1, about 0.5:1 to about25:1, about 0.5:1 to about 10:1, about 0.5:1 to about 5:1.

The ratio, by weight, of alkyl 3-hydroxybutyrate to the total amount ofwater and surfactant in the cleaning composition can be at least about0.001:1, at least about 0.002:1, at least about 0.005:1, at least about0.010:1 and/or not more than about 0.25:1, not more than about 0.10:1,not more than about 0.05:1, or in the range of from about 0.001:1 toabout 0.25:1, about 0.001:1 to about 0.10:1, about 0.001:1 to about0.05:1, about 0.002:1 to about 0.25:1, about 0.002:1 to about 0.10:1,about 0.002:1 to about 0.05:1, about 0.005:1 to about 0.25:1, about0.005:1 to about 0.10:1, about 0.005:1 to about 0.05:1, about 0.010:1 toabout 0.25:1, about 0.010:1 to about 0.10:1, about 0.010:1 to about0.05:1.

The surfactant can be nonionic, cationic, anionic, amphoteric, orzwitterionic. When two or more surfactants are present in the cleaningcomposition, at least one of the surfactants may be of a different typethan one or more of the other surfactants. Alternatively, all of thesurfactants in a system comprising two or more surfactants can be of thesame type. The surfactant can have a hydrophilic-lipophilic balance(HLB) value of at least about 3, at least about 4, at least about 5, atleast about 6, at least about 7, at least about 8 and/or not more thanabout 19, not more than about 18, or not more than about 17, not morethan about 16, not more than about 15, not more than about 14, asdetermined by Griffin's Method. The HLB value of the surfactant can bein the range of from about 3 to about 19, about 3 to about 18, about 3to about 17, about 3 to about 16, about 3 to about 15, about 3 to about14, about 4 to about 19, about 4 to about 18, about 4 to about 17, about4 to about 16, about 4 to about 15, about 4 to about 14, about 5 toabout 19, about 5 to about 18, about 5 to about 17, about 5 to about 16,about 5 to about 15, about 5 to about 14, about 6 to about 19, about 6to about 18, about 6 to about 17, about 6 to about 16, about 6 to about15, about 6 to about 14, about 7 to about 19, about 7 to about 18, about7 to about 17, about 7 to about 16, about 7 to about 15, about 7 toabout 14, about 8 to about 19, about 8 to about 18, about 8 to about 17,about 8 to about 16, about 8 to about 15, about 8 to about 14. A list ofHLB values for a variety of suitable surfactants is available inMcCutcheon's Emulsifiers & Detergents, North American and InternationalEdition, MC Publishing Company, 1993. The HLB value of a particularsurfactant may be a function of its ionic nature.

The surfactant may comprise a nonionic surfactant. Examples of nonionicsurfactants include, but are not limited to, alkyl polyglucosides, fattyalcohols, glycols, glycol esters, alkyl carboxylic acid esters, alcoholalkoxylates, alkyl phenol alkoxylates, nonylphenol ethoxylates, alkylethanolamides, amine oxides, terpene alkoxylates, or combinationsthereof. Some additional examples of nonionic surfactants includeethoxylated alkanolamides, ethylene bisamides, fatty acid esters,glycerol esters, ethoxylated fatty acid esters, sorbitan esters,ethoxylated sorbitan, tristyrylphenol ethoxylates, mercaptanethoxylates, end-capped and EO/PO block copolymers such as ethyleneoxide/propylene oxide block copolymers, chlorine capped ethoxylates,tetra-functional block copolymers, lauramine oxide, cocamine oxide,stearamine oxide, stearamidopropylamine oxide, palmitamidopropylamineoxide, decylamine oxide, decyl alcohol, lauryl alcohol, tridecylalcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, oleylalcohol, linoleyl alcohol and linolenyl alcohol, ethoxylated laurylalcohol, trideceth alcohols, lauric acid, oleic acid, stearic acid,myristic acid, cetearic acid, isostearic acid, linoleic acid, linolenicacid, ricinoleic acid, elaidic acid, arichidonic acid, myristoleic acid,and combinations thereof. The non-ionic surfactant may also comprise aglycol such as polyethylene glycol, polypropylene glycol or derivativesthereof and/or one or more alkyl polyethylene glycol esters.

Further examples of nonionic surfactants can include, but are notlimited to, substituted aliphatic or aromatic alcohol ethoxylates,beta-alkyloxy alkane sulfonates, phenol ethoxylates or alkylphenolethoxylates. Other nonionic surfactants can include ethoxylated tallowalkyl amine (polyoxyethylene tallow amine), commercially available asGENAMIN T 150M from Clariant Corp. or as MILSTAT N-20 from ICI Americasor an ethoxylated coco alkyl amine (polyoxyethylene coco amine),commercially available as ETHOMEEN C/25 from Akzo Nobel.

Additionally, the surfactant utilized in the inventive cleaningcomposition can comprise one or more nonionic surfactants formed from amixture of polyethoxylated alkanol of the general formula:CH₃(CH₂)_(m)—(O—CH₂—CH₂)_(n)—OH wherein m is an integer from 8 to 12 andn represents an average degree of ethoxylation for the mixture, whichcan be at least about 2 moles, at least about 3 moles, at least about 4moles and/or not more than about 8 moles, not more than about 7 moles,not more than about 6 moles. Examples of these types of surfactants caninclude NEODOL™ ethoxylates, commercially available from Shell Company,USA, which include higher aliphatic, a primary alcohol containingbetween 9 and 11 carbon atoms (i.e., a C₉-C₁₁ alkanol), condensed withbetween 2.5 and 10 moles of ethylene oxide (e.g., NEODOL™ 91-2.5,NEODOL™ 91-5, NEODOL™ 91-6), a NEODOL™ 91-8), a C₁₂-15 alkanol condensedwith 6.5 moles ethylene oxide (NEODOL™ 23-6.5), C₁₂-C₁₅ alkanolcondensed with 12 moles ethylene oxide (e.g., NEODOL™ 25-12), a C₁₄-C₁₅alkanol condensed with 13 moles ethylene oxide (e.g., NEODOL™ 45-13), aC₁₄-C₁₅ alkanol condensed with about 7 moles of ethylene oxide (e.g.,NEODOL™ 45-7) and the like.

Still other suitable nonionic surfactants are those derived from C₁₁-C₁₅secondary alkanols by reaction with either 9 moles of ethylene oxide(e.g., Tergitol™ 15-S-9) or 12 moles of ethylene oxide (e.g., Tergitol™15-S-12), both of which are commercially available from UnionCarbide/Dow Chemical. Other examples of nonionic surfactants include thealkyl phenol ethoxylates including nonyl phenol condensed with between 3and 9.5 moles of ethylene oxide per mole of nonyl phenol; dinonyl phenolcondensed with 12 moles of ethylene oxide per mole of phenol; dinonylphenol condensed with 15 moles of ethylene oxide per mole of phenol anddi-isoctylphenol condensed with 15 moles of ethylene oxide per mole ofphenol. Such surfactants are commercially available as Igepal™ CO-630nonyl phenol ethoxylate available from Rhodia, Inc. (La Defense,France).

Additional nonionic surfactants which may be used include condensationproducts of a C₈-C₂₀ alkanol with a mixture of ethylene oxide andpropylene oxide may also be used. The weight ratio of ethylene oxide topropylene oxide can be about 2.5:1 to about 4:1 or about 2.8:1 to about3.3:1, with the total of the ethylene oxide and propylene oxide(including the terminal ethanol or propanol group) being at least about60 percent, at least about 70 percent and/or not more than about 85percent, not more than about 80 percent. Such surfactants arecommercially available from BASF-Wyandotte (Michigan, USA). Further,other suitable nonionic surfactants include the condensates of between 2and 30 moles of ethylene oxide with sorbitan mono- and tri-C₁₀-C₂₀alkanoic acid esters. These types of surfactants are commerciallyavailable under the TWEEN trade name from Imperial Chemical Industries(London, UK).

Further examples of suitable surfactants include, but are not limitedto, polyoxyethylene (4) sorbitan monolaurate, polyoxyethylene (4)sorbitan monostearate, polyoxyethylene (20) sorbitan trioleate andpolyoxyethylene (20) sorbitan tristearate and compounds formed bycondensing ethylene oxide with a hydrophobic base, which is formed bythe condensation of propylene oxide with propylene glycol. The molecularweight of the hydrophobic portion of the molecule is at least about 950g/mol, at least about 1500 g/mol and/or not more than about 4000 g/mol,not more than about 2500 g/mol, or in the range of from about 950 toabout 4000 g/mol, about 950 to about 2500 g/mol, about 1500 to about4000 g/mol or 1500 to 2500 g/mol, and the addition of polyoxyethyleneradicals to the hydrophobic portion tends to increase the solubility ofthe molecule as a whole, thereby making the surfactant water-soluble.The molecular weight of the block polymers vary between about 1,000g/mol and 15,000 g/mol and the polyethylene oxide content may be presentin an amount of about 20 weight percent to about 80 weight percent. Suchsurfactants are marketed under the trade name PLURONICS and,specifically, grades L62 and L64, commercially available from BASF.

The surfactant comprise an anionic surfactant such as, for example, analkylbenzene sulfonate, α-olefin sulfonate, paraffin sulfonate, alkylester sulfonate, alkyl sulfate, alkyl alkoxy sulfate, alkyl sulfonate,alkyl alkoxy carboxylate, monoalkyl phosphate, dialkyl phosphate,sarcosinate, sulfosuccinate, isethionate, taurate, or combinationsthereof. Other anionic surfactants that can be suitable for use in thecleaning composition of the present invention include ammonium laurylsulfate, ammonium laureth sulfate, triethylamine lauryl sulfate,triethylamine laureth sulfate, triethanolamine lauryl sulfate,triethanolamine laureth sulfate, monoethanolamine lauryl sulfate,monoethanolamine laureth sulfate, diethanolamine lauryl sulfate,diethanolamine laureth sulfate, lauric monoglyceride sodium sulfate,sodium lauryl sulfate, sodium laureth sulfate, potassium lauryl sulfate,potassium laureth sulfate, sodium-monoalkyl phosphates, sodium dialkylphosphates, sodium lauroyl sarcosinate, lauroyl sarcosine, cocoylsarcosine, ammonium cocyl sulfate, sodium cocyl sulfate, sodiumtrideceth sulfate, sodium tridecyl sulfate, ammonium trideceth sulfate,ammonium tridecyl sulfate, sodium cocoyl isethionate, disodium laurethsulfosuccinate, sodium methyl oleoyl taurate, sodium laurethcarboxylate, sodium trideceth carboxylate, potassium cocyl sulfate,monoethanolamine cocyl sulfate, sodium tridecyl benzene sulfonate, andsodium dodecyl benzene sulfonate.

Additional anionic surfactants can include salts of an alkali metal, analkali earth metal, ammonia, or a tetraalkylammonium ion and analkylsulfate, alkylsulfonic acid, or fatty acid. One example of such amaterial is the sulfate of a fatty alcohol, such as, for example, sodiumlauryl sulfate, or sulfate of a polyethoxylated alkanol having theformula: CH₃(CH₂)_(m)—(O—CH₂—CH₂)_(n)—OSO₃M, wherein M is a cation of analkali metal, alkaline earth metal, ammonium or polyalkanol ammonium ionor a di- or tri-ethanol or propanol ammonium salt; m is an integerbetween 6 and 14 inclusive, and may be 11 or 12; and n represents theaverage degree ethoxylation for the mixture, which is between 1 and 9inclusive or is preferably 2 moles. A specific example of this type ofsurfactant is C₁₂-C₁₃ alcohol polyethylene glycol (ethoxy) ethersulfate. Other examples of anionic surfactants can include, but are notlimited to, sulfonates or carboxylates of optionally substitutedaromatic or aliphatic alcohol, such as, for example, sulfonates orcarboxylates of alkanol, phenol, arylalkanol, alkylphenol, or olefinicalcohol.

Other suitable anionic surfactants may be reaction products of fattyacids esterified with isethionic acid and neutralized with sodiumhydroxide. The fatty acids used in these surfactants may be derivedfrom, for example, coconut oil or palm kernel oil. Also suitable aresodium or potassium salts of fatty acid amides of methyl tauride. Stillother anionic surfactants may be succinnates, such as, for example,disodium N-octadecylsulfosuccinnate; disodium lauryl sulfosuccinate,diammonium lauryl sulfosuccinate, tetrasodiumN-(1,2-dicarboxyethyl)-N-octadecylsulfosuccinnate, and the diamyl,dihexyl, and dioctyl esters of sodium sulfosuccinic acid. Additionally,suitable anionic detersive surfactants include olefin sulfonates havingabout 10 to about 24 carbon atoms. In addition to the true alkenesulfonates and a proportion of hydroxy-alkanesulfonates, the olefinsulfonates can contain minor amounts of other materials, such as alkenedisulfonates depending upon the reaction conditions, proportion ofreactants, the nature of the starting olefins and impurities in theolefin stock and side reactions during the sulfonation process.

The surfactant may comprise a cationic surfactant. The cationicsurfactant can include a quaternary ammonium compound. Somerepresentative examples of quaternary ammonium compounds include cetyltrimethyl ammonium bromide (also known as CETAB or cetrimonium bromide),cetyl trimethyl ammonium chloride (also known as cetrimonium chloride),myristyl trimethyl ammonium bromide (also known as myrtrimonium bromideor quaternium-13), stearyl dimethyl distearyldimonium chloride, dicetyldimonium chloride, stearyl octyldimonium methosulfate, dihydrogenatedpalmoylethyl hydroxyethylmonium methosulfate, isostearyl benzylimidoniumchloride, cocoyl benzyl hydroxyethyl imidazolinium chloride, dicetyldimonium chloride, distearyldimonium chloride,isostearylaminopropalkonium chloride, olealkonium chloride,behentrimonium chloride, and combinations thereof.

Additional examples of suitable cationic surfactants can include, butare not limited to, mono- and di-alkyl chain cationic surfactants.Examples of suitable mono-alkyl chain cationic surfactants include thosehaving one long alkyl chain having between 12 to 22 carbon atoms or from16 to 22 carbon atoms or a C₁₈-C₂₂ alkyl group. The remaining groupsattached to nitrogen are independently selected from an alkyl group offrom 1 to about 4 carbon atoms or an alkoxy, polyoxyalkylene,alkylamido, hydroxyalkyl, aryl or alkylaryl group having up to about 4carbon atoms. Such mono-alkyl cationic surfactants may include, forexample, mono-alkyl quaternary ammonium salts and mono-alkyl amines.Mono-alkyl quaternary ammonium salts may include those having anon-functionalized long alkyl chain. Mono-alkyl amines can includemono-alkyl amidoamines and salts thereof. Other suitable examples ofmono-long alkyl quaternized ammonium salt cationic surfactants arebehenyl trimethyl ammonium salt, stearyl trimethyl ammonium salt, cetyltrimethyl ammonium salt, and hydrogenated tallow alkyl trimethylammonium salt.

Mono-alkyl amines may also be suitable for use in the cleaningcompositions described herein as cationic surfactants. Primary,secondary, and tertiary fatty amines may be used. Tertiary amido amineshaving an alkyl group of from 12 to 22 carbons may be used. Exemplarytertiary amido amines include, but are not limited to,stearamidopropyldimethylamine, stearamidopropyldiethylamine,stear-amidoethyldiethylamine, stearamidoethyldimethylamine,palmitamidopropyldimethylamine, palmitamidopropyldiethylamine,palmitamidoethyldiethylamine, palmit-amidoethyldimethylamine,behenamidopropyldimethylamine, behenamidopropyldiethylamine,behenamidoethyldiethylamine, behenamidoethyldimethylamine,arachnid-amidopropyldimethylamine, arachidamidopropyldiethylamine,arachidamidoethyldiethylamine, arachidamidoethyldimethylamine,diethylaminoethylstearamide, and combinations thereof.

Additionally, one or more of the amines listed above may be used incombination with acids such as 1-glutamic acid, lactic acid,hydrochloric acid, malic acid, succinic acid, acetic acid, fumaric acid,tartaric acid, citric acid, 1-glutamic hydrochloride, maleic acid, andmixtures thereof. Mono-alkyl chain cationic surfactants may be usedalone, or may be used in combination with other cationic surfactantssuch as di-alkyl chain cationic surfactants. Suitable di-alkyl chaincationic surfactants can include, for example, dialkyl (C₁₄-C₁₈)dimethyl ammonium chloride, ditallow alkyl dimethyl ammonium chloride,dihydrogenated tallow alkyl dimethyl ammonium chloride, distearyldimethyl ammonium chloride, and dicetyl dimethyl ammonium chloride, andcombinations thereof.

The surfactant may comprise an amphoteric surfactant. When used in acleaning composition of the present invention, the amphoteric surfactantmay comprise an alkali metal, alkaline earth metal, ammonium salt of analkyl amphocarboxy glycinate, substituted ammonium salt of an alkylamphocarboxy glycinate, alkyl amphocarboxypropionate, alkylamphodipropionate, alkyl amphodiacetate, alkyl amphoglycinate, alkylamphopropionate, alkyl iminopropionate, alkyl iminodipropionate, alkylamphopropylsulfonate, or combinations thereof. Some specific examples ofamphoteric surfactants include cocoamphoacetate, cocoamphopropionate,cocoamphodiacetate, lauroamphoacetate, lauroamphodiacetate,lauroamphodipropionate, lauroamphodiacetate, cocoamphopropyl sulfonatecaproamphodiacetate, caproamphoacetate, caproamphodipropionate, andstearoamphoacetate.

Other exemplary amphoteric surfactants can include, but are not limitedto, amphocarboxylates such as alkylamphoacetates (mono or di), alkylbetaines, amidoalkyl betaines, amidoalkyl sultaines, amphophosphates,phosphorylated imidazolines such as phosphobetaines andpyrophosphobetaines, carboxyalkyl alkyl polyamines,alkylimino-dipropionates, alkylamphoglycinates (mono or di),alkylamphoproprionates (mono or di), N-alkyl β-aminoproprionic acids,alkylpolyamino carboxylates, and mixtures thereof. In some cases, theamphoteric surfactants may not require a counter-ion. However, in otherinstances, a counter-ion may be present and, when present, can originatefrom an alkali metal, an alkaline earth metal, or ammonia.

The surfactant may comprise a zwitterionic surfactant. Examples ofzwitterionic surfactants can include, but are not limited to, alkylbetaines, amidoalkyl betaines, sulfobetaine, imidazoline, propinate, orcombinations thereof. Some examples of zwitterionic surfactants includecocodimethyl carboxymethyl betaine, lauryl dimethyl carboxymethylbetaine, lauryl dimethyl α-carboxy-ethyl betaine, cetyl dimethylcarboxymethyl betaine, lauryl bis-(2-hydroxy-ethyl)carboxy methylbetaine, stearyl bis-(2-hydroxy-propyl)carboxymethyl betaine, oleyldimethyl gamma-carboxypropyl betaine, and lauryl bis-(2-hydroxypropyl)α-carboxyethyl betaine, amidopropyl betaines, and alkyl sultaines, suchas cocodimethyl sulfopropyl betaine, stearyldimethyl sulfopropylbetaine, lauryl dimethyl sulfoethyl betaine, laurylbis-(2-hydroxy-ethyl)sulfopropyl betaine, and alkylamidopropylhydroxysultaines.

The cleaning composition may include not more than about 10 weightpercent, not more than about 8 weight percent, not more than about 6weight percent, not more than about 5 weight percent, not more thanabout 4 weight percent, not more than about 3 weight percent, not morethan about 2 weight percent, not more than about 1 weight percent, notmore than about 0.5 weight percent, not more than about 0.25 weightpercent of one or more components other than the alkyl3-hydroxybutyrate, water, and at least one surfactant, based on thetotal weight of the composition.

The cleaning composition may, however, include one or more additives inaddition to the alkyl 3-hydroxybutyrate, water, and surfactant, whenpresent. These additives may be used to impart additional functionality,properties, or characteristics to the final composition. When present,the additives can be selected from the group consisting of co-solvents,complexing agents, dyes, fragrances, perfumes, pH stabilizers,acidifiers, preservatives, defoaming agents, metal protectants,antioxidants, bactericides, fungicides, disinfectants, thickeners, fineor coarse grits, polymers, buffers, delaminates, whiteners, brighteners,solubilizers, builders, corrosion inhibitors, lotions, mineral oils,cloud point modifiers, ion exchangers, sudsing control agents, soilremoval agents, softening agents, opacifiers, inert diluents, grayinginhibitors, enzymes, and combinations thereof.

The one or more additional components may be present in the cleaningcompositions of the present invention in an amount of at least about0.001 weight percent, at least about 0.005 weight percent, at leastabout 0.01 weight percent, at least about 0.05 weight percent, at leastabout 0.10 weight percent, at least about 0.15 weight percent, at leastabout 0.50 weight percent, at least about 1 weight percent, at leastabout 1.5 weight percent, at least about 2 weight percent and/or notmore than about 40 weight percent, not more than about 35 weightpercent, not more than about 30 weight percent, not more than about 25weight percent, not more than about 20 weight percent, not more thanabout 15 weight percent, not more than about 10 weight percent, not morethan about 8 weight percent, not more than about 5 weight percent, notmore than about 4 weight percent, not more than about 3 weight percent,not more than about 2 weight percent, not more than about 1 weightpercent, based on the total weight of the composition.

The additives may be present in the cleaning composition in an amount inthe range of from about 0.001 to about 40 weight percent, 0.001 to about35 weight percent, 0.001 to about 30 weight percent, 0.001 to about 25weight percent, about 0.001 to about 20 weight percent, about 0.001 toabout 15 weight percent, about 0.001 to about 10 weight percent, about0.001 to about 8 weight percent, about 0.001 to about 5 weight percent,about 0.001 to about 4 weight percent, about 0.001 to about 3 weightpercent, about 0.001 to about 2 weight percent, about 0.001 to about 1weight percent, about 0.005 to about 40 weight percent, 0.005 to about35 weight percent, 0.005 to about 30 weight percent, 0.005 to about 25weight percent, about 0.005 to about 20 weight percent, about 0.005 toabout 15 weight percent, about 0.005 to about 10 weight percent, about0.005 to about 8 weight percent, about 0.005 to about 5 weight percent,about 0.005 to about 4 weight percent, about 0.005 to about 3 weightpercent, about 0.005 to about 2 weight percent, about 0.005 to about 1weight percent, about 0.01 to about 40 weight percent, 0.01 to about 35weight percent, 0.01 to about 30 weight percent, 0.01 to about 25 weightpercent, about 0.01 to about 20 weight percent, about 0.01 to about 15weight percent, about 0.01 to about 10 weight percent, about 0.01 toabout 8 weight percent, about 0.01 to about 5 weight percent, about 0.01to about 4 weight percent, about 0.01 to about 3 weight percent, about0.01 to about 2 weight percent, about 0.01 to about 1 weight percent,about 0.05 to about 40 weight percent, 0.05 to about 35 weight percent,0.05 to about 30 weight percent, 0.05 to about 25 weight percent, about0.05 to about 20 weight percent, about 0.05 to about 15 weight percent,about 0.05 to about 10 weight percent, about 0.05 to about 8 weightpercent, about 0.05 to about 5 weight percent, about 0.05 to about 4weight percent, about 0.05 to about 3 weight percent, about 0.05 toabout 2 weight percent, about 0.05 to about 1 weight percent, about 0.10to about 40 weight percent, 0.10 to about 35 weight percent, 0.10 toabout 30 weight percent, 0.10 to about 25 weight percent, about 0.10 toabout 20 weight percent, about 0.10 to about 15 weight percent, about0.10 to about 10 weight percent, about 0.10 to about 8 weight percent,about 0.10 to about 5 weight percent, about 0.10 to about 4 weightpercent, about 0.10 to about 3 weight percent, about 0.10 to about 2weight percent, about 0.10 to about 1 weight percent, about 0.15 toabout 40 weight percent, 0.15 to about 35 weight percent, 0.15 to about30 weight percent, 0.15 to about 25 weight percent, about 0.15 to about20 weight percent, about 0.15 to about 15 weight percent, about 0.15 toabout 10 weight percent, about 0.15 to about 8 weight percent, about0.15 to about 5 weight percent, about 0.15 to about 4 weight percent,about 0.15 to about 3 weight percent, about 0.15 to about 2 weightpercent, about 0.15 to about 1 weight percent, about 0.50 to about 40weight percent, about 0.50 to about 35 weight percent, about 0.50 toabout 30 weight percent, about 0.50 to about 25 weight percent, about0.50 to about 20 weight percent, about 0.50 to about 15 weight percent,about 0.50 to about 10 weight percent, about 0.50 to about 8 weightpercent, about 0.50 to about 5 weight percent, about 0.50 to about 4weight percent, about 0.50 to about 3 weight percent, about 0.50 toabout 2 weight percent, about 0.50 to about 1 weight percent, about 1 toabout 40 weight percent, 1 to about 35 weight percent, 1 to about 30weight percent, 1 to about 25 weight percent, about 1 to about 20 weightpercent, about 1 to about 15 weight percent, about 1 to about 10 weightpercent, about 1 to about 8 weight percent, about 1 to about 5 weightpercent, about 1 to about 4 weight percent, about 1 to about 3 weightpercent, about 1 to about 2 weight percent, about 1.5 to about 40 weightpercent, 1.5 to about 35 weight percent, 1.5 to about 30 weight percent,1.5 to about 25 weight percent, about 1.5 to about 20 weight percent,about 1.5 to about 15 weight percent, about 1.5 to about 10 weightpercent, about 1.5 to about 8 weight percent, about 1.5 to about 5weight percent, about 1.5 to about 4 weight percent, about 1.5 to about3 weight percent, about 1.5 to about 2 weight percent, about 2 to about40 weight percent, 2 to about 35 weight percent, 2 to about 30 weightpercent, 2 to about 25 weight percent, about 2 to about 20 weightpercent, about 2 to about 15 weight percent, about 2 to about 10 weightpercent, about 2 to about 8 weight percent, about 2 to about 5 weightpercent, about 2 to about 4 weight percent, about 2 to about 3 weightpercent, based on the total weight of the composition.

The ratio, by weight, of alkyl 3-hydroxybutyrate to the total amount ofsurfactant and additives in the cleaning composition can be at leastabout 0.002:1, at least about 0.005:1, at least about 0.010:1, at leastabout 0.050:1, at least about 0.10:1 and/or not more than about 150:1,not more than about 100:1, not more than about 50:1, not more than about25:1, not more than about 10:1, not more than about 5:1, not more thanabout 0.5:1, or in the range of from about 0.002:1 to about 150:1, about0.002:1 to about 100:1, about 0.002:1 to about 50:1, about 0.002:1 toabout 25:1, about 0.002:1 to about 10:1, about 0.002 to about 5:1, about0.002:1 to about 0.5:1, about 0.005:1 to about 150:1, about 0.005:1 toabout 100:1, about 0.005:1 to about 50:1, about 0.005:1 to about 25:1,about 0.005:1 to about 10:1, about 0.005:1 to about 5:1, about 0.005:1to about 0.5:1, about 0.010:1 to about 150:1, about 0.010:1 to about100:1, about 0.010:1 to about 50:1, about 0.010:1 to about 25:1, about0.010:1 to about 10:1, about 0.010:1 to about 5:1, about 0.010:1 toabout 0.5:1, about 0.050:1 to about 150:1, about 0.050:1 to about 100:1,about 0.050:1 to about 50:1, about 0.050:1 to about 25:1, about 0.050:1to about 10:1, about 0.050:1 to about 5:1, about 0.050:1 to about 0.5:1,about 0.10:1 to about 150:1, about 0.10:1 to about 100:1, about 0.10:1to about 50:1, about 0.10:1 to about 25:1, about 0.10:1 to about 10:1,about 0.10:1 to about 5:1, about 0.10 to about 0.5:1.

The cleaning composition may include a co-solvent. When present, theadditional organic solvent can be employed in the cleaning compositionwithin one or more of the ranges specified above. Depending, in part, onthe specific formulation and/or end use of the cleaning composition, theco-solvent may be used to enhance performance or, in some instances, maysimply be included in the composition to aid in coupling a furtheradditive such as, for example, a colorant, a preservative, or afragrance. The co-solvent may also be added to facilitate coupling ofthe water and alkyl 3-hydroxybutyrate described above and it can bebeneficial, in some cases, that the co-solvent be substantially watersoluble.

Suitable co-solvents can be selected from the group consisting of analiphatic or acyclic hydrocarbon, a halocarbon, a polyol, glycol ether,an ether, an ester of a glycol ether, an alcohol, an ester, a ketone,and combinations thereof. Specific examples of additional solventsinclude, but are not limited to, methyl acetate, ethyl acetate, methylpropionate, iso-propyl acetate, n-propyl acetate, iso-butyl acetate,n-butyl acetate, amyl acetate, methyl amyl acetate, ethyl propionate,n-propyl propionate, n-butyl propionate, methyl iso-butyrate,n-butyrate, isobutyl butyrate, isobutyl isobutyrate, 2-ethylhexylacetate, ethylene glycol diacetate, acetone, methyl ethyl ketone, methyln-propyl ketone, methyl isobutyl ketone, methyl iso-amyl ketone,diisobutyl ketone, cyclohexanone, methanol, ethanol, isopropanol,n-propanol, isobutanol, sec-butanol, n-butanol, t-pentyl alcohol,2,3-dimethyl-2-butanol, cyclohexanol, 2-ethyl hexanol, benzyl alcohol,ethylene glycol, propylene glycol, hexylene glycol, 1,3-propanediol,2-methyl-1,3-propanediol, diethyleneglycol, dipropyleneglycol, glycerol,formamide, acetamide, N-methylpyrrolidone, N,N-dimethylformamide,N,N-dimethylacetamide, sulfolane, dimethylsulfoxide,gamma-butyrolactone, propylene carbonate, ethylene glycol monopropylether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether,ethylene glycol 2-ethylhexyl ether, ethylene glycol phenyl ether,ethylene glycol butyl ether acetate, diethylene glycol monomethyl ether,diethylene glycol monoethyl ether, diethylene glycol monopropyl ether,diethylene glycol monobutyl ether, diethylene glycol monohexyl ether,diethylene glycol methyl ether acetate, diethylene glycol propyl etheracetate, diethylene glycol butyl ether acetate, triethylene glycolmonomethyl ether, triethylene glycol monoethyl ether, triethylene glycolmonopropyl ether, triethylene glycol monobutyl ether, propylene glycolmonomethyl ether, propylene glycol n-propyl ether, propylene glycoln-butyl ether, propylene glycol methyl ether acetate, dipropylene glycolmethyl ether, dipropylene glycol n-propyl ether, dipropylene glycoln-butyl ether, tripropylene glycol methyl ether, tripropylene glycoln-propyl ether, and tripropylene glycol n-butyl ether, ester derivativesthereof, and combinations thereof.

The cleaning composition may include at least one metal chelating agent.Examples of suitable chelating agents include, but are not limited to,triazoles, such as 1,2,4-triazole (TAZ), or triazoles substituted withsubstituents such as C₁-C₈ alkyl, amino, thiol, mercapto, imino, carboxyand nitro groups, such as benzotriazole (BTA), tolyltriazole,5-phenyl-benzotriazole, 5-nitro-benzotriazole,3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole,hydroxybenzotriazole, 2-(5-amino-pentyl)-benzotriazole,1-amino-1,2,3-triazole, 1-amino-5-methyl-1,2,3-triazole,3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole,3-isopropyl-1,2,4-triazole, 5-phenylthiol-benzotriazole,chloro-benzotriazoles, naphthotriazole, as well as thiazoles,tetrazoles, imidazoles, phosphates, thiols and azines such as2-mercaptobenzoimidizole (MBI), 2-mercaptobenzothiazole,4-methyl-2-phenylimidazole, 2-mercaptothiazoline, 5-aminotetrazole(ATA), 5-amino-1,3,4-thiadiazole-2-thiol,2,4-diamino-6-methyl-1,3,5-triazine, thiazole, triazine,methyltetrazole, 1,3-dimethyl-2-imidazolidinone,1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole,diaminomethyltriazine, mercaptobenzothiazole, imidazoline thione,mercaptobenzimidazole, 4-methyl-4H-1,2,4-triazole-3-thiol,5-amino-1,3,4-thiadiazole-2-thiol, benzothiazole, tritolyl phosphate,indiazole, ethylenediaminetetraacetic acid (EDTA),1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid (CDTA), catechol,gallic acid, thiophenol, nitrilotriacetic acid (NTA),N,N′-bis(2-hydroxyphenyl)ethylenediiminodiacetic acid (HPED),triethylenetetranitrilohexaacetic acid (TTNA), desferriferrioxaminB,N,N′,N″-tris[2-(N-hydroxycarbonyl)ethyl]-1,3,5-benzenetricarboxamide(BAMTPH), ethylenediaminediorthohydroxyphenylacetic acid (EDDHA),ethylenediaminetetramethylenephosphonic acid (EDTMP),α-(hydroxyimino)phosphonic acid, propylenediaminetetraacetic acid(PDTA), hydroxypropylenediaminetetraacetic acid (HPDTA),isoserinediacetic acid (ISDA), β-alaninediacetic acid (β-ADA),hydroxyethanediphosphonic acid, diethylenetriaminetetraacetic acid,diethylenetriaminetetramethylenephosphonic acid, 1-hydroxyethane, 1,1diphosphonic acid, methylene disphosphonic acid, hydroxymethylenediphosphonic acid, dichloromethylene disphosphonic acid,hydroxycyclohexylmethylene disphosphonic acid, 1-hydroxy-3-aminopropane1,1 diphosphonic acid, 1-hydroxy-4-aminobutane, 1,1 diphosphonic acid,hydroxyethyleneaminodiacetic acid, hydroxyethylethylenediaminetriaceticacid, diethylenetriaminepentaacetic acid, diethanolglycine,ethanolglycine, citric acid, glycolic acid, glyoxylic acid, acetic acid,lactic acid, phosphonic acid, glucoheptonic acid or tartaric acid,polyacrylates, carbonates, phosphonates, gluconates, dithiocarbamates,and combinations thereof.

Depending on the formulation, the cleaning composition may also includeone or more pH adjusting and/or buffering agents to control or maintainthe pH of the composition within a certain range. Examples of suitablepH adjusting and/or buffering agents include, but are not limited to,citric acid, lactic acid, glycolic acid, 3-hydroxybutenoic acid,glyceric acid, malic acid, tartaric acid, malonic acid, succinic acid,glutaric acid, adipic acid, maleic acid, fumaric acid and phtalic acidor alkaline compounds such as sodium and potassium carbonate,bicarbonate and hydroxide. Additionally, the composition may include apH buffering agent such as, for example, weak acids and the alkali metalor ammonium salts thereof such as boric acid, or an organic carboxylicacid such as lactic acid, maleic acid, ascorbic acid, malic acid,benzoic acid, fumaric acid, succinic acid, oxalic acid, malonic acid,mandelic acid, maleic anhydride, citric acid, phthalic acid, and otheraliphatic and aromatic carboxylic acids. Suitable ammonium salts caninclude, for example, tetralkylammonium salts of the above listed weakacids, wherein the tetralkylammonium ion is represented by [NR₁R₂R₃R₄]⁺,where R₁, R₂, R₃ and R₄ may be the same as or different from one anotherand are selected from the group consisting of C₁-C₆ straight-chained orbranched alkyl (e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl) orC₆-C₁₀ substituted or unsubstituted aryl groups (e.g., benzyl).

With or without a pH adjusting or buffering agent, the cleaningcomposition may have a pH of at least about 4, at least about 4.5, atleast about 5, at least about 5.5, and/or not more than about 8, notmore than about 7.5, not more than about 7, not more than about 6.5, notmore than about 6. The pH of the composition can be about 4 to about 8,about 4 to about 7.5, about 4 to about 7, about 4 to about 6.5, about 4to about 6, about 4.5 to about 8, about 4.5 to about 7.5, about 4.5 toabout 7, about 4.5 to about 6.5, about 4.5 to about 6, about 5 to about8, about 5 to about 7.5, about 5 to about 7, about 5 to about 6.5, about5 to about 6, about 5.5 to about 8, about 5.5 to about 7.5, about 5.5 toabout 7, about 5.5 to about 6.5, about 5.5 to about 6.

The cleaning composition of the present invention can also include atleast one fragrance. When present, the fragrance may be incorporatedinto the composition in an amount of at least about 0.01 weight percent,at least about 0.05 weight percent, at least about 0.10 weight percent,at least about 0.50 weight percent, at least about 1 weight percentand/or not more than about 5 weight percent, not more than about 4weight percent, not more than about 3 weight percent, not more thanabout 2 weight percent. The fragrance may be present in the cleaningcomposition in an amount in the range of from about 0.01 to about 5weight percent, about 0.01 to about 4 weight percent, about 0.01 toabout 3 weight percent, about 0.01 to about 2 weight percent, about 0.05to about 5 weight percent, about 0.05 to about 4 weight percent, about0.05 to about 3 weight percent, about 0.05 to about 2 weight percent,about 0.10 to about 5 weight percent, about 0.10 to about 4 weightpercent, about 0.10 to about 3 weight percent, about 0.10 to about 2weight percent, about 0.50 to about 5 weight percent, about 0.50 toabout 4 weight percent, about 0.50 to about 3 weight percent, about 0.50to about 2 weight percent, about 1 to about 5 weight percent, about 1 toabout 4 weight percent, about 1 to about 3 weight percent, about 1 toabout 2 weight percent, based on the total weight of the composition.

Examples of suitable fragrances can include, but are not limited to,synthetic oils and/or ethanolic natural plant extract. The fragrance canbe present in a concentrated form, or as an aqueous solution or incombination with an organic solvent carrier, such as ethanol. Suitableaqueous (e.g. steam-distilled), alcoholic or aqueous alcoholic plantextracts can originate from leaves, fruits, blossoms, roots, rinds orstems of aloe, pineapple, artichoke, arnica, avocado, valerian, bamboo,henbane, birch, stinging nettle, echinacea, ivy, wild angelica, gentian,ferns, pine needles, silver weed, ginseng, broom, oat, rose hip,hamamelis, hay flowers, elderberry, hop, coltsfoot, currants, chamomile,carrots, chestnuts, clover, burr root, cocoanut, cornflower, limeblossom, lily of the valley, marine algae, balm, mistletoe, passionflower, ratanhia, marigold, rosemary, horse chestnut, pink hawthorn,sage, horsetail, yarrow, primrose, nettle, thyme, walnut, wine leaves,and white hawthorn. The fragrance, when present in the cleaningcomposition, can include one or more of these or other similarcomponents. Alternatively, the cleaning composition of the presentinvention may be un-fragranced.

The cleaning composition may also include at least one preservative.When present, the preservative may be incorporated into the compositionin an amount of at least about 0.001 weight percent, at least about0.005 weight percent, at least about 0.010 weight percent and/or notmore than about 2 weight percent, not more than about 1.5 weightpercent, not more than about 1 weight percent. The preservative can bepresent in the cleaning composition in an amount in the range of fromabout 0.001 to about 2 weight percent, about 0.001 to about 1.5 weightpercent, about 0.001 to about 1 weight percent, about 0.005 to about 2weight percent, about 0.005 to about 1.5 weight percent, about 0.005 toabout 1 weight percent, about 0.010 to about 2 weight percent, about0.010 to about 1.5 weight percent, about 0.010 to about 1 weightpercent, based on the total weight of the composition. Examples ofsuitable preservatives include, but are not limited to,methylchloroisothiazolinone, methylisothiazolinone, glutaraldehyde,1,2-benzisothiazoline-3-one, polyhexa-methylenebiguanide hydrochloride,phenoxyethanol, methylparaben, propyl P-hydroxybenzoate (propylparaben), and sodium benzoate.

The cleaning composition can also include at least one defoaming agent.When present in the cleaning composition, the defoaming agent can bepresent in an amount of at least about 0.001 weight percent, at leastabout 0.005 weight percent, at least about 0.010 weight percent and/ornot more than about 2 weight percent, not more than about 1.5 weightpercent, not more than about 1 weight percent, based on the total weightof the composition. The defoaming agent can be present in the cleaningcomposition in an amount in the range of from about 0.001 to about 2weight percent, about 0.001 to about 1.5 weight percent, about 0.001 toabout 1 weight percent, about 0.005 to about 2 weight percent, about0.005 to about 1.5 weight percent, about 0.005 to about 1 weightpercent, about 0.010 to about 2 weight percent, about 0.010 to about 1.5weight percent, about 0.010 to about 1 weight percent, based on thetotal weight of the composition. Examples of suitable defoaming agentscan include, but are not limited to, silica dispersed in polydimethylsiloxane, polydimethyl siloxane, and functionalized polydimethylsiloxanes, hydrocarbon oils and waxes, fatty esters, alcohols, soaps,and ethoxylates, polyethylene glycol esters, alkyl phosphate esters, andcombinations thereof.

Additionally, the cleaning composition can include one or more metalprotectants, such as, for example, sodium gluconate or sodiumglucoheptonate. When present, the metal protectant can be incorporatedinto the composition in an amount of at least about 0.05 weight percent,at least about 0.10 weight percent, at least about 0.15 weight percentand/or not more than about 5 weight percent, not more than about 4weight percent, not more than about 3 weight percent. The cleaningcomposition can include a metal protectant present in an amount in therange of about 0.05 to about 5 weight percent, about 0.05 to about 4weight percent, about 0.05 to about 3 weight percent, about 0.10 toabout 5 weight percent, about 0.10 to about 4 weight percent, about 0.10to about 3 weight percent, about 0.15 to about 5 weight percent, about0.15 to about 4 weight percent, about 0.15 to about 3 weight percent,based on the total weight of the composition.

The cleaning composition of the present invention can be dyed orun-dyed. If dyed, the composition may include at least one dye in anamount of at least in an amount of at least about 0.05 weight percent,at least about 0.10 weight percent, at least about 0.50 weight percentand/or not more than about 5 weight percent, not more than about 4weight percent, not more than about 3 weight percent, not more thanabout 2 weight percent. The cleaning composition can include a dyepresent in an amount in the range of about 0.05 to about 5 weightpercent, about 0.05 to about 4 weight percent, about 0.05 to about 3weight percent, about 0.05 to 2 weight percent, about 0.10 to about 5weight percent, about 0.10 to about 4 weight percent, about 0.10 toabout 3 weight percent, about 0.10 to about 2 weight percent, about 0.50to about 5 weight percent, about 0.50 to about 4 weight percent, about0.50 to about 3 weight percent, about 0.50 to about 2 weight percent,based on the total weight of the composition.

The dye can be an anionic dye. Examples of suitable anionic dyes caninclude, but are not limited to, Acid Black 1, Acid Blue 1, Acid Blue 3,Food Blue 5, Acid Blue 7, Acid Blue 9, Acid Blue 74, Acid Orange 3, AcidOrange 6, Acid Orange 7, Acid Orange 10, Acid Red 1, Acid Red 14, AcidRed 18, Acid Red 27, Acid Red 50, Acid Red 52, Acid Red 73, Acid Red 87,Acid Red 88, Acid Red 92, Acid Red 155, Acid Red 180, Acid Violet 9,Acid Violet 43, Acid Violet 49, Acid Yellow 1, Acid Yellow 23, FoodYellow No. 8, D&C Brown No. 1, D&C Green No. 5, D&C Green No. 8, D&COrange No. 4, D&C Orange No. 10, D&C Red No. 21, D&C Red No. 27, D&C RedNo. 33, D&C Violet 2, D&C Yellow No. 7, D&C Yellow No. 8, D&C Yellow No.10, FD&C Red 2, FD&C Red 40, FD&C Red No. 4, FD&C Yellow No. 6, FD&CBlue 1, Food Black 1, Food Black 2, Disperse Black 9 and Disperse Violet1 and sodium or potassium salts thereof. Neutral dyes may also be usedin the present invention, representative examples being HC Blue No. 2,HC Blue No. 4, HC Blue No. 11, HC Brown No. 1, HC Brown No. 2, HC GreenNo. 1, HC Orange No. 1, HC Orange No. 2, HC Orange No. 5, HC Red BN, HCRed No. 1, HC Red No. 9, HC Red No. 10, HC Violet BS, HC Violet No. 1,HC Violet No. 2, HC Yellow No. 2, HC Yellow No. 9, HC Yellow No. 10, HCYellow No. 11, and HC Yellow No. 15. The dye may also be nonionic.

Whether dyed or un-dyed, the cleaning composition may be visually clear,transparent, translucent, or opaque, depending, at least in part, on itsparticular formulation and/or its ultimate form. For example, thecleaning composition can comprise a visually clear, homogenous solutionor a visually clear or transparent microemulsion. Alternatively, thecleaning compositions described herein may comprise an emulsion and maybe translucent, cloudy, or even opaque.

The present invention also relates to a method of making a cleaningcomposition that comprises combining at least one 3-alkylhydroxybutyrate as described in detail previously with water and anoptional surfactant to provide a cleaning mixture. The combining can becarried out at approximately ambient conditions such as, for example, atemperature of at least about 20° C., at least about 25° C., at leastabout 27° C. and/or not more than about 80° C., not more than about 70°C., not more than about 60° C., not more than about 50° C., not morethan about 40° C., not more than about 30° C. The combining temperaturecan be, for example, in the range of from about 20 to about 80° C.,about 20 to about 70° C., about 20 to about 60° C., about 20 to about50° C., about 20 to about 40° C., about 20 to about 30° C., about 25 toabout 80° C., about 25 to about 70° C., about 25 to about 60° C., about25 to about 50° C., about 25 to about 40° C., about 25 to about 30° C.,about 27 to about 80° C., about 27 to about 70° C., about 27 to about60° C., about 27 to about 50° C., about 27 to about 40° C., about 27 toabout 30° C. The temperature at which the components are combined can bewithin about 40°, within about 20°, within about 10°, or within about 5°of ambient temperature.

The alkyl 3-hydroxybutyrate, water, and optional surfactant, can becombined according to several suitable methods. For example, thecombining can include mixing the alkyl 3-hydroxybutyrate with thesurfactant to form a homogenous mixture and then adding the homogenousmixture to the water under strong agitation to form a cleaning mixture.In another example, the combining can include mixing the water andsurfactant to form an aqueous homogenous mixture and adding the alkyl3-hydroxybutyrate to the aqueous homogenous mixture to form the cleaningmixture. Alternatively, the water and alkyl 3-hydroxybutyrate can becombined to form a mixture to which the surfactant, when employed, maybe added to form the cleaning mixture.

When the composition includes one or more additional components, such asthe additives listed above, the additional component may be added to thehomogenous mixture prior to, simultaneous with, or subsequent toaddition of the alkyl 3-hydroxybutyrate. Preferably, in some case, theadditive, when present, may be added after the water, alkyl3-hydroxybutyrate, and surfactant, if present, have been combined.Depending on the formulation, a pH value of the resulting mixture may betaken and, based on the measured pH, one or more acids, bases, and/orbuffers may be added to the mixture in order to obtain a final pH forthe cleaning composition in the ranges provided above.

The combining of components to form the cleaning composition may be atleast partially carried out using mechanical agitation, especially whenthe intermediate or final cleaning mixture comprises a solution ormicro-emulsion. When a high degree of mixing is desired, the agitationof components can be at least partially carried out using a high speedblender, a high pressure valve homogenizer, a membrane, amicro-structured system, ultra sound, or other device capable ofexerting a high shear force to the mixture. Additionally, mixers such asplanetary or sigma-blade mixers may also be used. Emulsions may also beformed using the equipment or methods described above, but can typicallybe made using less intense agitation and lower shear force. Any suitableform of agitation capable of mixing the components with enough intensityto provide the desired end product may be used to form the cleaningmixture.

The resulting cleaning mixture formulated as described above can be inthe form of a solution, an emulsion, or a micro-emulsion. When thecleaning composition is a solution, it may be a homogenous solution andmay be clear, transparent, translucent, or opaque. When the cleaningcomposition is an emulsion or micro-emulsion, it may be an oil-in-wateremulsion, with droplets of the alkyl 3-hydroxybutyrate being dispersedin the continuous water phase, or a water-in-oil emulsion with dropletsof water dispersed in a continuous alkyl 3-hydroxybutyrate phase,although the former is preferred. Micro-emulsions can be clear,transparent, translucent, or opaque, while emulsions can be translucentor opaque. When the cleaning composition is an emulsion ormicroemulsion, it may include at least one surfactant and/or at leastone co-solvent, including those described in detail previously, alongwith the alkyl 3-hydroxybutyrate, with the alkyl 3-hydroxybutyrate beingpresent, for example, in an amount of at least 4 weight percent, basedon the total weight of the composition. When the cleaning composition isa solution, however, it may or may not include a surfactant. If nosurfactant is present, the cleaning composition may include the alkyl3-hydroxybutyrate in an amount of not more than about 4 weight percent,not more than about 3.5 weight percent, not more than about 3 weightpercent, or not more than about 2.5 weight percent, based on the totalweight of the composition.

Whether a solution, a micro-emulsion, or an emulsion, the cleaningcomposition of the present invention may be clear, transparent, oropaque. If an emulsion, the composition can be a stable emulsion atstorage and use temperatures of at least about 0° F., at least about 15°F., at least about 20° F., at least about 35° F. and/or not more than80° F., not more than about 75° F., not more than about 70° F., not morethan about 65° F. The cleaning compositions of the present invention canbe solutions, emulsions, or micro-emulsions stable at storage and usetemperatures in the range of from about 0 to about 80° F., about 0 toabout 75° F., about 0 to about 70° F., about 0 to about 65° F., about 15to about 80° F., about 15 to about 75° F., about 15 to about 70° F.,about 15 to about 65° F., about 20 to about 80° F., about 20 to about75° F., about 20 to about 70° F., about 20 to about 65° F., about 35 toabout 80° F., about 35 to about 75° F., about 35 to about 70° F., about35 to about 65° F.

The cleaning mixture resulting from the above-described combining stepmay be a “ready-to-use” (RTU) formulation or a concentrate. In somecases, RTU formulations can be solutions or micro-emulsions, whileconcentrates can be micro-emulsions or emulsions. Whether the cleaningcomposition is a concentrate or an RTU formulation, it may include analkyl 3-hydroxybutyrate, water, a surfactant, and an additive of thetypes and/or in the amount listed above.

In one exemplary RTU formulation, the cleaning composition can includean alkyl 3-hydroxybutyrate in an amount of at least about 0.1 weightpercent, at least about 0.5 weight percent, at least about 1 weightpercent, and/or not more than about 10 weight percent, not more thanabout 5 weight percent, not more than about 3 weight percent, based onthe total weight of the composition. In one example, an RTU formulationcan include an alkyl 3-hydroxybutyrate in an amount in the range of fromabout 0.1 to about 10 weight percent, about 0.1 to about 5 weightpercent, about 0.1 to about 3 weight percent, about 0.5 to about 10weight percent, about 0.5 to about 5 weight percent, about 0.5 to about3 weight percent, about 1 to about 10 weight percent, about 1 to about 5weight percent, about 1 to 3 weight percent, based on the total weightof the composition.

In the same or a different exemplary RTU formulation, water may bepresent in an amount of at least about 75 weight percent, at least about80 weight percent, at least about 85 weight percent, at least about 90weight percent and/or not more than about 99.9 weight percent, not morethan about 99 weight percent, not more than about 98 weight percent, notmore than about 97 weight percent, not more than about 95 weightpercent, or in an amount in the range of from about 75 to about 99.9weight percent, about 75 to about 99 weight percent, about 75 to about98 weight percent, about 75 to about 97 weight percent, about 75 toabout 95 weight percent, about 80 to about 99.9 weight percent, about 80to about 99 weight percent, about 80 to about 98 weight percent, about80 to about 97 weight percent, about 80 to about 95 weight percent, fromabout 85 to about 99.9 weight percent, about 85 to about 99 weightpercent, about 85 to about 98 weight percent, about 85 to about 97weight percent, about 85 to about 95 weight percent, from about 90 toabout 99.9 weight percent, about 90 to about 99 weight percent, about 90to about 98 weight percent, about 90 to about 97 weight percent, about90 to about 95 weight percent, based on the total weight of thecomposition.

In the same or a different exemplary RTU formulation, the ratio of alkyl3-hydroxybutyrate to water in the cleaning composition can be at leastabout 0.002:1, at least about 0.003:1, at least about 0.005:1 and/or notmore than about 0.040:1, not more than about 0.035:1, not more thanabout 0.030:1 or in the range of from about 0.002:1 to about 0.040:1,about 0.002:1 to about 0.035:1, about 0.002:1 to about 0.030:1, about0.003:1 to about 0.040:1, about 0.003:1 to about 0.035:1, about 0.003:1to about 0.030:1, about 0.005:1 to about 0.040:1, about 0.005:1 to about0.035:1, about 0.005:1 to about 0.030:1, based on the total weight ofsaid composition.

In the same or a different RTU formulation, the total amount ofsurfactant and additives present in the cleaning composition can be anamount of at least about 0.1 weight percent, at least about 0.5 weightpercent, at least about 1 weight percent, at least about 2 weightpercent and/or not more than about 20 weight percent, not more thanabout 10 weight percent, not more than about 8 weight percent, not morethan about 6 weight percent, not more than about 5 weight percent, or anamount in the range of from about 0.1 to about 20 weight percent, about0.1 to about 10 weight percent, about 0.1 to about 8 weight percent,about 0.1 to about 6 weight percent, 0.1 to about 5 weight percent,about 0.5 to about 20 weight percent, about 0.5 to about 10 weightpercent, about 0.5 to about 8 weight percent, about 0.5 to about 6weight percent, 0.5 to about 5 weight percent, about 1 to about 20weight percent, about 1 to about 10 weight percent, about 1 to about 8weight percent, about 1 to about 6 weight percent, 1 to about 5 weightpercent, about 2 to about 20 weight percent, about 2 to about 10 weightpercent, about 2 to about 8 weight percent, about 2 to about 6 weightpercent, 2 to about 5 weight percent, based on the total weight of thecomposition.

When the cleaning composition (or cleaning mixture) is a concentrate, itcan optionally be diluted with one or more diluents, such as, forexample, water prior to use as a cleaning composition. Alternatively,the concentrate itself may be used as a cleaning composition.

In one exemplary concentrate formulation, the cleaning composition caninclude an alkyl 3-hydroxybutyrate in an amount of at least about 0.5weight percent, at least about 1 weight percent, at least about 5 weightpercent and/or not more than about 15 weight percent, not more thanabout 10 weight percent, based on the total weight of the composition.In one example, an RTU formulation can include an alkyl3-hydroxybutyrate in an amount in the range of from about 0.5 to about15 weight percent, about 0.5 to about 10 weight percent, about 1 toabout 15 weight percent, about 1 to about 10 weight percent, about 5 toabout 15 weight percent, about 5 to about 10 weight percent, based onthe total weight of the composition.

In the same or a different exemplary RTU formulation, water may bepresent in an amount of at least about 30 weight percent, at least about40 weight percent, at least about 50 weight percent and/or not more thanabout 90 weight percent, not more than about 80 weight percent, not morethan about 75 weight percent, not more than about 65 weight percent, orin an amount in the range of from about 30 to about 90 weight percent,about 30 to about 80 weight percent, about 30 to about 75 weightpercent, about 30 to about 65 weight percent, about 40 to about 90weight percent, about 40 to about 80 weight percent, about 40 to about75 weight percent, about 40 to about 65 weight percent, about 50 toabout 90 weight percent, about 50 to about 80 weight percent, about 50to about 75 weight percent, about 50 to about 65 weight percent, basedon the total weight of the composition.

In the same or a different exemplary concentrate formulation, the ratioof alkyl 3-hydroxybutyrate to water in the cleaning composition can beat least about 0.01:1, at least about 0.03:1, at least about 0.05:1and/or not more than about 0.50:1, not more than about 0.25:1, not morethan about 0.20:1 or in the range of from about 0.01:1 to about 0.50:1,about 0.01:1 to about 0.25:1, about 0.01:1 to about 0.20:1, about 0.03:1to about 0.50:1, about 0.03:1 to about 0.25:1, about 0.03:1 to about0.20:1, about 0.05:1 to about 0.50:1, about 0.05:1 to about 0.25:1,about 0.05:1 to about 0.20:1, based on the total weight of saidcomposition.

In the same or a different exemplary concentrate formulation, the totalamount of surfactant and additives present in the cleaning mixture canbe at least about 2 weight percent, at least about 5 weight percent, atleast about 10 weight percent, at least about 20 weight percent, atleast about 25 weight percent, at least about 30 weight percent, and/ornot more than about 90 weight percent, not more than about 85 weightpercent, not more than about 80 weight percent, not more than about 75weight percent, not more than about 70 weight percent, not more thanabout 65 weight percent, not more than about 60 weight percent, based onthe total weight of the composition.

The total amount of surfactant and additives present can be in the rangeof from about 2 to about 90 weight percent, about 2 to about 85 weightpercent, about 2 to about 80 weight percent, about 2 to about 75 weightpercent, about 2 to about 70 weight percent, about 2 to about 65 weightpercent, about 2 to about 60 weight percent, about 5 to about 90 weightpercent, about 5 to about 85 weight percent, about 5 to about 80 weightpercent, about 5 to about 75 weight percent, about 5 to about 70 weightpercent, about 5 to about 65 weight percent, about 5 to about 60 weightpercent, about 10 to about 90 weight percent, about 10 to about 85weight percent, about 10 to about 80 weight percent, about 10 to about75 weight percent, about 10 to about 70 weight percent, about 10 toabout 65 weight percent, about 10 to about 60 weight percent, about 20to about 90 weight percent, about 20 to about 85 weight percent, about20 to about 80 weight percent, about 20 to about 75 weight percent,about 20 to about 70 weight percent, about 20 to about 65 weightpercent, about 20 to about 60 weight percent, about 25 to about 90weight percent, about 25 to about 85 weight percent, about 25 to about80 weight percent, about 25 to about 75 weight percent, about 25 toabout 70 weight percent, about 25 to about 65 weight percent, about 25to about 60 weight percent, about 30 to about 90 weight percent, about30 to about 85 weight percent, about 30 to about 80 weight percent,about 30 to about 75 weight percent, about 30 to about 70 weightpercent, about 30 to about 65 weight percent, about 30 to about 60weight percent, based on the total weight of the composition.

When formulated as a concentrate, the cleaning composition of thepresent invention may be diluted, using at least one diluent such as,for example water or a liquid comprising water, to form an RTUformulation prior to use. The dilution ratio, by weight, of concentrateto water (or other diluent) can be at least about 1:80, at least about1:50, at least about 1:20, or at least about 1:10 and/or not more than10:1, not more than about 8:1, not more than about 5:1, not more thanabout 3:1, not more than about 2:1, not more than about 1:1. Thedilution ratio, by weight, of concentrate to water can be in the rangeof from about 1:80 to 10:1, about 1:80 to about 8:1, about 1:80 to about5:1, about 1:80 to about 3:1, about 1:80 to about 2:1, about 1:80 toabout 1:1, 1:50 to 10:1, about 1:50 to about 8:1, about 1:50 to about5:1, about 1:50 to about 3:1, about 1:50 to about 2:1, about 1:50 toabout 1:1, about 1:20 to 10:1, about 1:20 to about 8:1, about 1:20 toabout 5:1, about 1:20 to about 3:1, about 1:20 to about 2:1, about 1:20to about 1:1, about 1:10 to 10:1, about 1:10 to about 8:1, about 1:10 toabout 5:1, about 1:10 to about 3:1, about 1:10 to about 2:1, about 1:10to about 1:1.

The present invention also concerns a method of using a cleaningcomposition that comprises contacting a substrate with a cleaningcomposition comprising water and at least one alkyl 3-hydroxybutyrate asdefined by formula (I), above. The cleaning composition may also includea surfactant and one or more additional components of the types and inthe amounts as described in detail previously.

The method of the present invention can be used to clean a wide varietyof substrates. As used herein, the term “clean” means to remove at leasta portion of one or more undesired materials from a substrate. Thesubstrate being cleaned may present a hard surface at least partiallyformed of one or more materials selected from the group consisting ofmetal, glass, plastic, ceramic, porcelain, fiberglass, stone, concrete,plaster, brick, marble, vinyl, natural or composite wood, wall board, orcombinations thereof. Some substrates may be composite substrates,formed of two or more different materials, while others may be formed ofa single material. At least a portion of the substrate may be coatedwith a coating material, such as paint or polymeric coating material,different from the material of the underlying portion of the substrateor the portion of the substrate being contacted may be uncoated. Otherexemplary surface materials include, but are not limited to, glazed orunglazed tile, porcelain, ceramics, marble, granite, stainless steel,aluminum, polyester, painted and unpainted wood, painted or unpainted,concrete, plaster, no-wax vinyl, linoleum, melamine, FORMICA™, CORIAN™,and chromed substrates.

The type of soil able to be removed from one or more of the above-listedsubstrates by the cleaning composition is not particularly limited andcan include hydrophilic soils, hydrophobic soils, and neutral soils. Thesoils can be organic or inorganic and can have an acidic, neutral, orbasic pH. The soil can comprise, for example, dirt, tar, grease, oil,soap scum, protein, organics, enzymes, and combinations thereof. Incontrast to many conventional cleaning compositions, the cleaningcompositions of the present invention may have a hydrophobic cleaningefficiency of at least 90 percent achieved in less than 1000 strokes. Ingeneral, the cleaning efficiency of a cleaning composition can bedefined as the amount of a particular soil removed from a specific typeof substrate achieved within a given number of strokes, as visuallymeasured by evaluating the percentage of cleaned surface area. Specificprocedures for measuring various cleaning efficiencies are provided inExample 4.

As used herein, the “hydrophobic cleaning efficiency” of a givencomposition refers to the ability of the composition to remove bakedgrease from an aluminum substrate according to the baked grease scrubtest procedure outlined in Examples 2-4. The hydrophobic cleaningefficiency of a cleaning composition is measured by evaluating thepercentage of the surface area of the aluminum substrate that has beencleaned of the baked grease as a result of the baked grease scrub testdescribed in Examples 2-4 after a given number of strokes. Cleaningcompositions of the present invention may have a hydrophobic cleaningefficiency of at least about 90 percent, at least about 95 percent, orat least about 99 percent in less than 1,000 strokes and/or can have ahydrophobic cleaning efficiency of at least 90 percent achievable inless than about 950 strokes, less than about 900 strokes, less thanabout 850 strokes, less than about 800 strokes, less than about 750strokes, less than about 700 strokes, or less than about 650 strokesmeasured according to the baked grease scrub test described in Examples2-4.

Alternatively, or in addition, cleaning compositions according to thepresent invention may have a hydrophilic cleaning efficiency of at least90 percent achievable in less than 500 strokes. As used herein, the“hydrophilic cleaning efficiency” of a cleaning composition refers tothe ability of the composition to remove soap scum from a painted wallboard substrate according to the soap scum scrub test procedure outlinedin Examples 2-4. Hydrophilic cleaning efficiency is measured byevaluating the percentage of the surface area of the painted wall boardsubstrate that has been cleaned of the soap scum using the soap scumscrub test procedure described in Examples 2-4 after a given number ofstrokes. Cleaning compositions of the present invention may have ahydrophilic cleaning efficiency of at least about 90 percent, at leastabout 95 percent, or at least about 99 percent in less than 500 strokesand/or can have a hydrophobic cleaning efficiency of at least 90 percentachievable in less than about 500 strokes, less than about 450 strokes,less than about 400 strokes, less than about 350 strokes, less thanabout 300 strokes, less than about 250 strokes, or less than about 200strokes, less than about 150 strokes, less than about 125 strokes, lessthan about 100 strokes, measured according to the soap scum scrub testprocedure described in Examples 2-4.

In addition to being formulated as an RTU or dilatable concentrate asdescribed above, the cleaning compositions of the present invention mayalso be formulated as or incorporated into other forms, including, butnot limited to, gels, pastes, slurries, foams, wipes, sprays, andaerosols and may be applied to the substrate using any suitable method,such as, for example, wiping, spraying, foaming, soaking, scrubbing, andcombinations thereof. When using the cleaning composition of the presentinvention, at least a portion of the contacting can be carried out byapplying at least a portion of the cleaning composition with a spraynozzle, a pressurized spray nozzle, a sponge, a cloth, a wipe, a bucket,a pad, a scrubber, a brush, a hose, or combinations thereof.

As part of the method of cleaning a substrate described herein, at leasta portion of the cleaning composition used to contact the substrate maysubsequently be removed. In some cases, the cleaning composition, onceapplied, is allowed to remain on the substrate for some period of timebefore being removed. This “soak period,” measured from the end of theapplication of the composition to the substrate to the beginning of theremoval of at least a portion of the cleaning composition from thesubstrate, can be of any suitable duration. The length of the soak timecan be, for example, at least about 10 seconds, at least about 30seconds, at least about 1 minute, at least about 5 minutes, and/or notmore than about 1 day, not more than about 8 hours, not more than about4 hours, not more than about 2 hours, not more than about 1 hour, notmore than about 30 minutes, not more than about 5 minutes, not more thanabout 1 minute, not more than about 30 seconds.

The “soak period” can have a length in the range of from about 10seconds to about 1 day, about 10 seconds to about 8 hours, about 10seconds to about 4 hours, about 10 seconds to about 2 hours, about 10seconds to about 1 hour, about 10 seconds to about 30 minutes, about 10seconds to about 5 minutes, about 10 seconds to about 1 minute, about 10seconds to about 30 seconds, about 30 seconds to about 1 day, about 30seconds to about 8 hours, about 30 seconds to about 4 hours, about 30seconds to about 2 hours, about 30 seconds to about 1 hour, about 30seconds to about 30 minutes, about 30 seconds to about 5 minutes, about30 seconds to about 1 minute, about 1 minute to about 1 day, about 1minute to about 8 hours, about 1 minute to about 4 hours, about 1 minuteto about 2 hours, about 1 minute to about 1 hour, about 1 minute toabout 30 minutes, about 1 minute to about 5 minutes, about 5 minutes toabout 1 day, about 5 minutes to about 8 hours, about 5 minutes to about4 hours, about 5 minutes to about 2 hours, about 5 minutes to about 1hour, about 5 minutes to about 30 minutes.

In some cases, there may be no or substantially no soak time. Forexample, the soak period can be not more than about 10 seconds, not morethan about 8 seconds, not more than about 5 seconds, not more than about2 seconds, not more than about 1 second. Alternatively, the cleaningcomposition can be applied and removed simultaneously or nearlysimultaneously from at least a portion of the substrate.

During removal, at least a portion of the cleaning composition may berinsed from the substrate using a rinse fluid, applied in the same or adifferent way than the cleaning composition. The rinse fluid may be anaqueous rinse fluid comprising water or may simply be water. The rinsefluid may also include one or more additional additives and may, in somecases, be mixed with a cleaning composition of the same or differentformulation than the cleaning composition being rinsed from thesubstrate. After being at least partially rinsed, the substrate mayagain be re-contacted with a cleaning composition having the same or adifferent composition, which can then be rinsed again in a similarmanner. The steps of rinsing and repeating contacting depends on thesoil type and level of desired clean and can be repeated at least 2, 3,or 4 times.

The above-described method of cleaning a substrate may be sufficient toremove at least about 60, at least about 70, at least about 75, at leastabout 80, at least about 85, at least about 90, at least about 95, atleast about 97, at least about 99, or substantially all of the soil fromthe substrate. When a substrate is soiled by two different types ofsoil, the cleaning composition and method described above may be capableof removing at least about 40, at least about 50, at least about 60, atleast about 70, at least about 80, at least about 90 percent of eachtype of soil. Even when the soils are of different types, such as, forexample, hydrophilic and hydrophobic soils, the cleaning compositions ofthe present invention may be capable of such removal.

The cleaning compositions of the present invention can be domestic orhousehold cleaners, suitable for cleaning a variety of householdsubstrates, or may be specifically formulated for commercial,industrial, and/or institutional use. In some cases, the composition maybe usable in all three settings with no loss of performance. The uses ofthe cleaning compositions described herein are diverse and one or moreof the compositions may comprise or be used in a descaling composition,a bathroom cleaner, a toiled cleaner, a glass cleaner, a floor cleaner,a biocidal cleaner, an automotive cleaner, a wood cleaner, a plasticcleaner, a paint stripper, a degreasing composition, a desoilingcomposition, and/or an all-purpose general cleaner.

The type of substrate being contacted can be located in nearly any typeof environment. The substrate may, for example, present a hard surfacethat can be a domestic surface located in a kitchen, bathroom, laundryroom, garage, automobile, basement, outdoor area, and the like. Thesubstrate being cleaned may comprise an industrial and/or institutionalsubstrate associated with, for example, an industrial or institutionalkitchen, bathroom, laundering area, or laboratory, and/or the substratemay be a medical substrate, a clinical substrate, or may be a substrateassociated with transportation equipment including, for example,automobiles, airplanes, trains, subways, boats, and the like. Examplesof specific types of substrates can include, but are not limited to,floors, walls, tiles, windows, sinks, showers, bathtubs, showercurtains, wash basins, drains, dishes, fixtures, fittings, counter tops,cabinets, stove tops, appliance surfaces, such as internal and externalsurfaces of refrigerators, microwave ovens, convection ovens, freezers,dishwashers, washing machines, and dryers. The substrate may also beassociated with furniture or a portion of a transportation device, suchas an interior, exterior, or engine surface of a car, boat, plane, ortrain.

The following examples are intended to be illustrative of the presentinvention in order to teach one of ordinary skill in the art to make anduse the invention and are not intended to limit the scope of theinvention in any way.

EXAMPLES

The following Examples describe the preparation of several cleaningformulations, as well as the preparation of several types of soils andthe use of those soils to prepare various soiled panels on which thecleaning formulations were tested. As described below, the testsperformed included both qualitative and quantitative evaluations ofseveral comparative and inventive compositions.

Example 1 Formulation of Cleaning Compositions

Several cleaning formulations were prepared using the followingprocedure. First, a base stock solution was prepared by combining water,a nonionic ethoxylated alcohol surfactant (TOMADOL® 901 commerciallyavailable from Air Products and Chemicals Incorporated, Allentown, Pa.),a 31.8 w/w percent solution of cocoyl propyl betaine in water, an EDTAcomplexing agent, and sodium carbonate. The amounts of each of theseingredients in the base stock solution are summarized in Table 1, below.

TABLE 1 Cleaning Formulation Base Stock Solution Amount, PartsIngredient by Weight Water 94.50 Surfactant 0.50 Betaine 0.25 EDTA 2.00Sodium carbonate 0.50 Total 97.75

Next, 2.25 parts by weight, based on the total cleaning composition, ofseveral inventive and comparative solvents were added to severalaliquots of the base stock solution summarized in Table 1 above in orderto formulate Comparative Cleaning Compositions A-G and InventiveCleaning Compositions 1-4. The solvents used to formulate thesecompositions, along with a few select physical properties of eachsolvent, are summarized in Table 2, below.

TABLE 2 Summary of Solvents and Select Physical Properties thereof usedto Formulate Comparative Cleaning Compositions A-G and InventiveCleaning Compositions 1-4 Solvent Vapor Solvent Cleaning Pressure atBoiling Composition Solvent 20° C., torr Point, ° C. Comparative ADiethylene Glycol 0.12 198-204 Monoethyl Ether Comparative B DiethyleneGlycol 0.02 227-235 Monobutyl Ether Comparative C Dipropylene Glycol0.04 230 monobutyl ether Comparative D Benzyl Alcohol 0.076 205Comparative E Dibasic Ester 0.20 196-225 Comparative F d-limonene 1.5176 Comparative G Ethylene glycol 0.60 169-172 monobutyl ether Inventive1 n-butyl 0.06 217 3-hydroxybutyrate Inventive 2 i-butyl 0.08 2103-hydroxybutyrate Inventive 3 2-butyl 0.098 206 3-hydroxybutyrateInventive 4 i-propyl 0.17 169 3-hydroxybutyrate

Example 2 Formulation of Soiled Panels

Several soiled panels were created to test the cleaning efficiency ofthe compositions formulated in Example 1 against various types of dirton different surfaces.

Soap Scum on Painted Wallboard

A soap scum soil was produced according to the following procedure.First, a hard water sample was prepared by dissolving 10 grams ofcalcium acetate and 3 grams of magnesium nitrate in 1 liter of deionizedwater. Next, a soap solution was prepared by dissolving 100 grams ofIVORY brand soap (commercially available from Proctor & Gamble Company,Cincinnati, Ohio) in 1 liter of deionized water. Next, the severalingredients, the types and amounts of which are summarized in Table 3below, were mixed thoroughly and refrigerated to form a synthetic sebumcomposition.

TABLE 3 Ingredients for Preparation of Synthetic Sebum IngredientAmount, grams Palmitic Acid 10 Stearic Acid 5 Coconut oil 15 CetylEsters Wax² 10 Olive oil 20 Squalene 5 Cholesterol 10 Corn oil 15Linoleic Acid 10 Total 100

The soap scum was then prepared by mixing 500 mL of the hard watersample and 50 mL of the soap solution for 15 minutes and then filteringthe mixture through #41 filter paper using a Buchner funnel. The residueremaining on the filter was mixed with 2 grams of graphite power in 200mL of isopropyl alcohol for 10 minutes. Thereafter, 4 grams of thesynthetic sebum was added and the mixture was allowed to mix for another10 minutes.

The resulting soap scum was then applied to several dry wall boardsamples that had been previously painted with flat white paint accordingto ASTM D4488. Once applied, the soap scum was allowed to dry on thewall board before testing commenced.

Baked Greasy Soil on Aluminum

A greasy soil was prepared according to the A2 soil procedure outlinedin ASTM 4488 by combining 33 grams each of CRISCO-brand vegetableshortening, lard, and vegetable oil, along with 1 gram of graphitepowder over a steam bath. The ingredients were blended until smooth andthen refrigerated. The greasy soil was then applied to several aluminumQ-panels and baked in an oven at 100° C. for 4 hours, until the greaseformed a tough layer unable to be removed by mechanical cleaning.

Tar Soil on Aluminum

A tar soil blend was prepared according to the following procedure. Amixture of Tectyl 506, a viscous oil (commercially available fromPetroleum Service Company in Wilkes-Barr, Pa.), and Tectyl 121B, atar-like petroleum material also available from Petroleum ServiceCorporation, was formulated in a 10:90 weight ratio. The components wereheated during mixing to form a homogenous blend. Once blended, a layerof tar soil having a thickness of approximately 5 mils was applied toseveral aluminum Q-panels and the panels were allowed to air-dry for aperiod of 4 hours.

Tar Soil on Vinyl

A standardized tar soil blend was prepared according to theabove-described procedure. Once prepared, a 5-mil layer of tar soil wasapplied to several commercially available vinyl floor tiles and allowedto air dry for a period of 4 hours.

Example 3 Qualitative Scrub Testing of Comparative Cleaning CompositionsA-G and Inventive Cleaning Compositions 1-4

The effectiveness of Comparative Cleaning Compositions A-G and InventiveCleaning Compositions 1-4 were tested on several of the soiled panelsprepared in Example 2. During testing, the cleaning compositions wereapplied with a scrubbing machine constructed by modifying an MEK DoubleRub Test machine (commercially available from DJH, Inc. in Oakville,Ontario, Canada or Gardco in Pompano Beach, Fla.) to include a spongeholder instead of a hammer. The sponge holder was formed of a 4-inchaluminum cylinder having a %-inch internal diameter, with a holder ringinserted ½ inch from the bottom of the cylinder to hold the sponge inplace during cleaning at a fixed distance of ½ inch above the panelbeing cleaned.

To begin, a clean 1½ inch thick SCOTCH BRITE sponge, commerciallyavailable from 3M Company, St. Paul, Minn., was cut into severalcylindrical plugs having a height of 1½ inches and a diameter of¾inches. A first sponge plug was inserted into the machine holder andthe cleaning solution to be tested was poured onto the sponge from thetop until the sponge was visually saturated, but not flooded. Scrubbingcommenced using the scrubbing machine, using a method similar to theGardner scrub test with minimal friction between the sponge and surfacebeing cleaned. The scrubbing path was 0.8 inches wide and 2 inches long,with one stroke (two passes) taking 0.4 seconds.

Each of Comparative Cleaning Compositions A-G and Inventive CleaningCompositions 1-4 were tested on several soiled panels prepared asdescribed in Example 2. Each of the panels were scrubbed until theearlier of 1000 strokes or until the panel was clean. If the scrubbingstopped due to a cleaned panel, the number of strokes required toachieve that result was recorded. Additionally, one the scrubbing wasstopped, the operator observed each panel and evaluated its cleanlinessusing a qualitative rating scale with “10” indicating a completely cleanpanel and “2” indicating a panel with very little cleaning. Whenevaluating the cleaning compositions with wall board panels, theeffectiveness of the composition was not apparent when the board waswet. Therefore, a set number of scrubs (e.g., 25, 50, 100, etc.) wascarried out and the board was allowed to dry before evaluation.

Each of Comparative Cleaning Compositions A-G and Inventive CleaningCompositions 1-4 were tested on each of the soiled substrates preparedin Example 2. The results of the qualitative analysis are provided inTable 4, below.

TABLE 4 Qualitative Evaluations of Performance of Comparative CleaningCompositions A-G and Inventive Cleaning Compositions 1-4 on VariousSoiled Panels Grease on Tar on Tar on Soap Scum on Aluminum AluminumVinyl Wall board Type of Cleaning # Visual # Visual # Visual # VisualComposition Composition Scrubs Grade Scrubs Grade Scrubs Grade ScrubsGrade Comparative A 1000 2 1000 2 1000 5 200 2 Comparative B 1000 7 10003 1000 9 200 6 Comparative C 1000 3 700 8 1000 8 125 9 Comparative D 7004 800 8 1000 2 ne ne Comparative E 700 6 1000 8 1000 9 150 8 ComparativeF 600 7 1000 9 — — — — Comparative G 800 5 1000 4 — — 200 4 Inventive 1640 10 500 10 1000 10 100 10 Inventive 2 800 8 700 8 1000 8 100 10Inventive 3 1000 8 — — — — 100 8 Inventive 4 1000 5 1000 6 1000 6 200 4Notes: “ne” means not evaluated.

As shown in Table 4 above, for a given type of soil and panel, InventiveCompositions 1-4 tended to remove more soil, as indicated by higherscores, with fewer strokes than Comparative Cleaning Compositions A-G.In addition, as shown by the comparison of the performance of InventiveCompositions 1-4 for all types of soiled surfaces, the effectiveness ofcleaning compositions of the present invention is not limited to aparticular type of soil or surface. Instead, Inventive CleaningCompositions 1-4 have the ability to remove both hydrophobic (e.g., tar)and hydrophilic (e.g., soap scum) soils from several different types ofsurfaces.

Example 4 Quantitative Scrub Testing of Various Comparative andInventive Cleaning Compositions

Additional scrub tests were carried out to quantify the ability ofseveral cleaning compositions to remove different soils from a varietyof substrates. During testing, several comparative and inventivecleaning compositions were subjected to scrub tests as described abovein Example 3 in order to determine the number of strokes required toremove 90 percent of the soil from each panel, as measured by visualobservation. If the panel required more than a specified maximum numberof strokes for a given type of panel—i.e., more than 1000 strokes for analuminum panel and more than 500 strokes for painted wall board—the testwas stopped and the maximum number of strokes was recorded.

The above-described procedure was carried out using ComparativeCompositions B-H and Inventive Composition 1 to remove baked greasy soilfrom an aluminum panel (i.e., the baked grease scrub test) and to removetar from another aluminum panel (i.e., the tar-aluminum scrub test).Additionally, the procedure was carried out using ComparativeCompositions B-D and H and Inventive composition 1 to remove soap scumfrom painted wall board (i.e., the soap scum scrub test). Table 5,below, summarize the results, in number of strokes required to remove atleast 90 percent of the soil per visual inspection, for each of thecompositions and substrates listed above.

TABLE 5 Number of Strokes Required to Remove 90 percent of Soil from aPanel Soil/Substrate Grease on Tar on Soap Scum Type of CleaningAluminum Aluminum on Wall Board Composition Composition # Strokes #Strokes # Strokes Comparative A >1000 >1000 >500 ComparativeB >1000 >1000 300 Comparative C >1000 700 125 Comparative D >1000 900 —Comparative E >1000 900 — Comparative F >1000 >1000 — ComparativeG >1000 >1000 >500 Inventive 1 640 500 100

In addition, FIGS. 1-3 c show the appearance of each of the panelsresulting from these tests, with FIG. 1 illustrating the results foreach of the above compositions for removing grease from aluminum, FIG. 2showing results for each of the above compositions for removing tar fromaluminum, and FIGS. 3 a-c providing results for each of the abovecompositions for removing soap scum from painted wall board, with thenumber of strokes for each trial indicated below the specific run inFIGS. 3 a-3 c.

Additionally, the ability of several compositions to remove tar from avinyl panel within 1000 strokes was evaluated in a similar manner (i.e.,the tar-vinyl scrub test). The panels were prepared according to theprocedure described in Example 2, but, due to the difficulty of removingtar from unwaxed vinyl, each of the soiled panel was subjected to 1000strokes using the apparatus and method described in Example 3. After1000 strokes, the test was stopped and the results were evaluatedqualitatively in a similar manner as described in Example 3, with thecleaning ability of the composition being rated visually on a scale of 1to 10, with a “1” indicating a low level or no cleaning and a “10”indicating nearly or completely clean. The ratings assigned to eachcomposition are summarized in Table 6, below, with the results of thetest being shown in FIG. 4.

TABLE 6 Evaluation of Ability of Comparative and Inventive CleaningCompositions to Remove Tar from Vinyl at 1,000 Strokes Type of CleaningComposition Composition Rating Comparative A 3 Comparative B 3Comparative C 3 Comparative D 5 Comparative E 2 Comparative F 6Inventive 1 7 Inventive 4 4

Example 5 Interaction of Various Cleaning Solvents with Vinyl Flooring

Several tests were also conducted to determine the interaction ofseveral cleaning solvents used to formulate the cleaning compositions inExample 1 with the protective wax layer found on many types of vinylflooring. Vinyl flooring is typically waxed and buffed to a high glossand effectively removing soil from such flooring, especially soils liketar, is challenging because the dirt must be removed without harming thewax layer. To test the effect of several of the comparative andinventive solvents, in neat form, on the wax layer of a vinyl floortile, the following procedure was carried out.

An aqueous wax, commercially available from Zep, was mixed with a smallamount of fine graphite powder and applied to a vinyl floor tile with asubstantially uniform thickness. The wax layer was dried, buffed with acloth, and then allowed to dry overnight. After that, a second coat ofthe black-tinted wax was applied to the tile and was again dried,buffed, and allowed to dry overnight. A scrub test, as described abovein Example 3 was then run on several of the dried, waxed tiles, usingthe following solvents, in neat form: n-butyl 3-hydroxybutyrate (NBHB),isopropyl 3-hydroxybutyrate (IPHB), acetone, propylene glycol butylether (PnB), propylene glycol propyl ether (PnP), d-limonene,dipropylene glycol methyl ether (DPM), dibasic ester (DBE), and ethyleneglycol butyl ether (EB). The results are shown in FIG. 5.

As shown in FIG. 5, four of the solvents—n-butyl 3-hydroxybutyrate,isopropyl 3-hydroxybutyrate, d-limonene, and dibasic ester—did notremove the wax layer after 1000 strokes. The remaining solvents removedat least a portion of the wax layer, as indicated by the white streaksof underlying vinyl visible through the black-tinted wax. The number ofstrokes required to achieve the results shown in FIG. 5 for each of thesolvents tested are summarized in Table 7, below.

TABLE 7 Number of Strokes for Several Solvents in Wax Test Shown in FIG.5 Solvent # Strokes NBHB 1000 IPHB 1000 Acetone 50 PnB 500 PnP 500d-limonene 1000 DPM 1000 DBE 1000 EB 900

The preferred forms of the invention described above are to be used asillustration only, and should not be used in a limiting sense tointerpret the scope of the present invention. Obvious modifications tothe exemplary one embodiment, set forth above, could be readily made bythose skilled in the art without departing from the spirit of thepresent invention.

The inventors hereby state their intent to rely on the Doctrine ofEquivalents to determine and assess the reasonably fair scope of thepresent invention as pertains to any apparatus not materially departingfrom but outside the literal scope of the invention as set forth in thefollowing claims.

We claim:
 1. An aqueous cleaning composition comprising: water and atleast 0.1 weight percent of at least one alkyl 3-hydroxybutyrate definedby the following formula:

wherein R1 is selected from the group consisting of n-propyl, n-butyl,sec-butyl, tert-butyl, isopentyl, n-pentyl, 2-pentyl, 2-methylbutyl,3-pentyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, neopentyl, andcyclopentyl.
 2. The cleaning composition of claim 1, wherein R1 is analkyl group having three or four carbon atoms.
 3. The cleaningcomposition of claim 1, wherein R1 is an alkyl group selected from thegroup consisting of n-propyl, n-butyl, and sec-butyl.
 4. The cleaningcomposition of claim 1, wherein R1 is an alkyl group selected from thegroup consisting of n-butyl and sec-butyl.
 5. The cleaning compositionof claim 1, wherein R1 is an n-butyl group and wherein said alkyl3-hydroxybutyrate is present in said composition in an amount of atleast 0.5 weight percent, based on the total weight of said composition.6. The cleaning composition of claim 1, wherein said alkyl3-hydroxybutyrate has a vapor pressure of less than 0.10 torr measuredat 20° C.
 7. The cleaning composition of claim 1, wherein said alkyl3-hydroxybutyrate has a boiling point of at least 210° C.
 8. Thecleaning composition of claim 7, wherein said alkyl 3-hydroxybutyratehas a vapor pressure in the range of from 0.05 torr to about 0.09 torrmeasured at 20° C.
 9. The cleaning composition of claim 1, wherein saidalkyl 3-hydroxybutyrate has a flash point in the range of from about 80°C. to about 115° C. and an auto-ignition temperature in the range offrom about 290° C. and 345° C.
 10. The cleaning composition of claim 1,wherein said alkyl 3-hydroxybutyrate has a corn oil-water couplingefficiency in the range of from about 5 grams/gram to about 15grams/gram.
 11. The cleaning composition of claim 1, wherein said alkyl3-hydroxybutyrate is present in said cleaning composition in an amountin the range of from about 0.1 to about 50 weight percent, wherein saidwater is present in said cleaning composition in an amount in the rangeof from about 30 to about 99.9 weight percent, based on the total weightof said composition.
 12. The cleaning composition of claim 11, whereinthe ratio, by weight, of said alkyl 3-hydroxybutyrate to said water insaid cleaning composition is in the range of from about 0.005:1 to about0.50:1.
 13. The cleaning composition of claim 11, wherein said cleaningcomposition comprises less than 10 weight percent of components otherthan said water and said alkyl 3-hydroxybutyrate based on the totalweight of said composition.
 14. The cleaning composition of claim 1,wherein said alkyl 3-hydroxybutyrate is present in said cleaningcomposition in an amount in the range of from about 0.5 to about 3weight percent, based on the total weight of said composition.
 15. Thecleaning composition of claim 1, wherein said alkyl 3-hydroxybutyrate ispresent in said cleaning composition in an amount in the range of fromabout 1 to about 15 weight percent, based on the total weight of saidcomposition.
 16. The cleaning composition of claim 1, further comprisingat least one surfactant.
 17. The cleaning composition of claim 16,wherein said surfactant is present in said composition in an amount inthe range of from about 0.01 to about 15 weight percent, based on thetotal weight of said composition.
 18. The cleaning composition of claim16, wherein said composition comprises not more than 8 weight percent ofone or more components other than said alkyl 3-hydroxybutyrate, saidwater, and said surfactant.
 19. The cleaning composition of claim 16,wherein said at least one surfactant includes a mixture of two or moresurfactants each having a hydrophilic-lipophilic balance (HLB) value inthe range of from about 4 to about 16, wherein said mixture is presentin said cleaning composition in an amount in the range of from about0.05 to about 6 weight percent, based on the total weight of saidcomposition.
 20. The cleaning composition of claim 16, wherein theratio, by weight, of said alkyl 3-hydroxybutyrate to said surfactant insaid cleaning composition is in the range of from about 0.01:1 to about150:1.
 21. The cleaning composition of claim 16, wherein the ratio, byweight, of said alkyl 3-hydroxybutyrate to the total amount of saidwater and said surfactant in said cleaning composition is in the rangeof from about 0.001:1 to about 0.25:1.
 22. The cleaning composition ofclaim 16, further comprising at least one additive selected from thegroup consisting of a cosolvents, complexing agents, dyes, fragrances,pH stabilizers, preservatives, defoaming agents, metal protectants,antioxidants, bactericides, fungicides, thickeners, fine or coarsegrits, buffers, delaminates, whiteners, brighteners, solubilizers,builders, corrosion inhibitors, lotions, mineral oils, and enzymes. 23.The cleaning composition of claim 22, wherein said additive is presentin said cleaning composition in an amount of at least 0.001 to about 10weight percent, based on the total weight of said composition.
 24. Thecomposition of claim 23, wherein the ratio, by weight, of said alkyl3-hydroxybutyrate to the total amount of said surfactant and saidadditive is in the range of from about 0.002:1 to about 50:1.
 25. Thecleaning composition of claim 22, wherein the total amount of saidsurfactant and said additive present in said cleaning composition is inthe range of from about 5 to about 80 weight percent, based on the totalweight of said composition.
 26. The cleaning composition of claim 25,wherein the ratio, by weight, of said alkyl 3-hydroxybutyrate to thetotal amount of said water in said cleaning composition is in the rangeof from about 0.01:1 to 0.50:1.
 27. The cleaning composition of claim22, wherein the total amount of said surfactant and said additivepresent in said cleaning composition is in the range of from about 0.1to about 10 weight percent, based on the total weight of saidcomposition.
 28. The cleaning composition of claim 27, wherein theratio, by weight, of said alkyl 3-hydroxybutyrate to the total amount ofsaid water in said cleaning composition is in the range of from about0.005:1 to 0.035:1.
 29. The cleaning composition of claim 1, whereinsaid cleaning composition has a pH in the range of from about 4 to about8.
 30. The cleaning composition of claim 1, wherein said cleaningcomposition has a hydrophobic cleaning efficiency of at least 90 percentachieved in less than 1,000 strokes.
 31. The cleaning composition ofclaim 30, wherein said cleaning composition has a hydrophilic cleaningefficiency of at least 90 percent achieved in less than 500 strokes. 32.The cleaning composition of claim 1, wherein said cleaning compositionis in the form of an emulsion or a micro-emulsion.
 33. The cleaningcomposition of claim 1, wherein said cleaning composition is in the formof a homogenous solution.
 34. An aqueous cleaning compositioncomprising: (a) about 30 to about 99.9 weight percent of water; (b)about 0.5 to about 15 weight percent of at least one alkyl3-hydroxybutyrate defined by the following formula:

wherein R1 is an alkyl group having at least 3 and not more than 5carbon atoms; and (c) optionally, about 0.01 to about 15 weight percentof at least one surfactant, wherein each of the percentages are based onthe total weight of said composition, wherein the total weight ofcomponents other than said alky 3-hydroxybutyrate and said water in saidcleaning composition is not more than about 5 weight percent, based onthe total weight of said composition.
 35. The cleaning composition ofclaim 34, wherein R1 is selected from the group consisting of n-propyl,sec-butyl, and n-butyl.
 36. The cleaning composition of claim 34,wherein the pH of the composition is in the range of from about 4 toabout
 8. 37. The cleaning composition of claim 34, wherein the ratio, byweight, of alkyl 3-hydroxybutyrate to water in said cleaning compositionis in the range of from about 0.001:1 to 0.50:1.
 38. The cleaningcomposition of claim 34, wherein said surfactant is present in saidcomposition in an amount of at least 0.01 weight percent, wherein thetotal weight of components other than said alky 3-hydroxybutyrate, saidwater, and said surfactant in said cleaning composition is not more thanabout 4 weight percent, based on the total weight of said composition.39. The cleaning composition of claim 38, further comprising, adding anadditive to said cleaning mixture, wherein said additive is selectedfrom the group consisting of cosolvents, complexing agents, dyes,fragrances, pH stabilizers, preservatives, defoaming agents, metalprotectants, antioxidants, bactericides, fungicides, thickeners, fine orcoarse grits, buffers, delaminates, whiteners, brighteners,solubilizers, builders, corrosion inhibitors, lotions, mineral oils,enzymes, and combinations thereof.
 40. The cleaning composition of claim39, wherein the total amount of said additive and said surfactant insaid cleaning composition is in the range of from about 2 to about 75weight percent, based on the total weight of said composition, whereinthe ratio, by weight, of said alkyl 3-hydroxybutyrate to said water isin the range of from about 0.01:1 to about 0.5:1.
 41. The cleaningcomposition of claim 39, wherein the total amount of said additive andsaid surfactant in said cleaning composition is in the range of fromabout 0.1 to about 20 weight percent, based on the total weight of saidcomposition and wherein the ratio, by weight, of said alkyl3-hydroxybutyrate to said water is in the range of from about 0.001:1 toabout 0.035:1.
 42. The cleaning composition of claim 34, wherein saidcomposition has a hydrophobic cleaning efficiency of at least 90 percentin less than 1,000 strokes.
 43. The cleaning composition of claim 34,wherein said composition has a hydrophilic cleaning efficiency of atleast 90 percent in less than 500 strokes.
 44. An aqueous cleaningcomposition comprising: (a) at least one alkyl 3-hydroxybutyrate definedby the following formula:

wherein R1 is an alkyl group having at least 3 and not more than 5carbon atoms; (b) water; (c) at least one surfactant, wherein saidsurfactant is present in an amount of less than 4 weight percent, basedon the total weight of said composition; and (d) one or more optionaladditives other than said alkyl 3-hydroxybutyrate, said water, and saidsurfactant.
 45. The cleaning composition of claim 44, wherein said alkylgroup is selected from the group consisting of n-propyl, n-butyl,sec-butyl, tert-butyl, isopentyl, n-pentyl, 2-pentyl, 2-methylbutyl,3-pentyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, neopentyl, andcyclopentyl.
 46. The cleaning composition of claim 44, wherein saidalkyl group is selected from the group consisting of n-propyl, n-butyl,and sec-butyl.
 47. The cleaning composition of claim 44, wherein saidalkyl group is n-butyl.
 48. The cleaning composition of claim 44,wherein the ratio, by weight, of said alkyl 3-hydroxybutyrate to thetotal amount of said water and said surfactant in said composition is inthe range of from 0.002:1 to 5:1 and wherein the ratio, by weight, ofsaid alkyl 3-hydroxybutyrate to the total amount of said surfactant andsaid additives in said composition is less than 0.25:1.
 49. The cleaningcomposition of claim 44, wherein said composition includes less than 8weight percent of components other than said alkyl 3-hydroxybutyrate andsaid water, based on the total weight of said composition.
 50. Thecleaning composition of claim 44, wherein said composition includes lessthan 5 weight percent of said additives, based on the total weight ofsaid composition.
 51. The cleaning composition of claim 44, wherein saidalkyl 3-hydroxybutyrate has a boiling point of at least 210° C.
 52. Thecleaning composition of claim 50, wherein said alkyl 3-hydroxybutyratehas a vapor pressure in the range of from 0.05 torr to about 0.09 torrmeasured at 20° C.
 53. The cleaning composition of claim 44, wherein theratio, by weight, of said alkyl 3-hydroxybutyrate to the total amount ofsaid water in said composition is in the range of from about 0.005:1 to0.035:1.
 54. The cleaning composition of claim 44, wherein the totalamount of said surfactant and said additive present in said compositionis in the range of from about 0.1 to about 10 weight percent, based onthe total weight of said composition.